-
Notifications
You must be signed in to change notification settings - Fork 11
/
imap.html
1214 lines (890 loc) · 51.3 KB
/
imap.html
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<html>
<head>
<title>Allegro CL imap and pop interface</title>
<meta name="GENERATOR" content="Microsoft FrontPage 3.0">
</head>
<body>
<h1 align="center">Allegro CL imap and pop interface</h1>
<p align="left">copyright (c) Franz Inc.</p>
<p align="left"> </p>
<p align="left"><strong>imap</strong> is a client-server protocol for processing
electronic mail boxes. <strong>imap </strong>is the successor to the <strong>pop</strong>
protocol. It is <strong>not</strong> an upward compatible successor.
The main focus of this document is the <strong>imap</strong>
protocol. Only one small section describes the functions in the <strong>pop</strong>
interface.</p>
<p align="left">The contents of this document are:</p>
<ul>
<li><p align="left">the <strong>imap</strong> interface</p>
</li>
<li><p align="left"><a href="#pop">the <strong>pop</strong> interface</a></p>
</li>
<li><p align="left"><a href="#conditions">the <strong>conditions</strong> signaled by the <strong>imap</strong>
and <strong>pop</strong> interfaces.</a></p>
</li>
<li><p align="left"><a href="#smtp">the <strong>smtp</strong> interface</a> (used for
sending mail)</p>
</li>
</ul>
<p align="left">The imap interface is based on the Imap4rev1 protocol described in
rfc2060. Where this document is describing the actions of the imap commands it
should be considered a secondary source of information about those commands and rfc2060
should be considered the primary source.</p>
<p align="left">The advantages of <strong>imap</strong> over <strong>pop</strong> are:</p>
<ol>
<li><p align="left"><strong>imap </strong>can work with multiple mailboxes (<strong>pop </strong>works
with a single mailbox)</p>
</li>
<li><p align="left">With <strong>imap</strong> you're encouraged to leave mail in mailboxes
on the server machine, thus it can be read from any machine on the network.
With <strong>pop</strong> you're encouraged to download the mail to the client machine's
disk, and it thus becomes inaccessible to all other client machines.</p>
</li>
<li><p align="left"><strong>imap</strong> parses the headers of messages thus allowing
easier analysis of mail messages by the client program.</p>
</li>
<li><p align="left"><strong>imap</strong> supports searching messages for data and sorting
by date.</p>
</li>
<li><p align="left"><strong>imap </strong>supports annotating messages with flags, thus
making subsequent searching easier.</p>
</li>
</ol>
<p align="left"> </p>
<h1 align="left">Package</h1>
<p align="left">The functions in this interface are defined in the <strong>net.post-office</strong>
package. The previous version of this module gave this package the <strong>po</strong>
nickname. We've removed that nickname to reduce the possibility of clashing with
user-defined packages. You are free to add that nickname back if you so desire.</p>
<p align="left"> </p>
<h1 align="left">Mailboxes</h1>
<p align="left">Mailboxes are repositories for messages. Mailboxes are named
by Lisp strings. The mailbox "inbox" always exists and it is the mailbox
in which new messages are stored. New mailboxes can be created.
They can have simple names, like "foo" or they can have
hierarchical names (like "clients/california/widgetco"). After
connecting to an imap server you can determine what string of characters you must use
between simple names to create a hierarchical name (in this example "/" was the
separator character). </p>
<p align="left">Each mailbox has an associated unique number called its <strong>uidvalidity</strong>.
This number won't change as long as <strong>imap</strong> is the only
program used to manipulate the mailbox. In fact if you see that the number has
changed then that means that some other program has done something to the mailbox that
destroyed the information that <strong>imap</strong> had been keeping about the
mailbox. In particular you can't now retrieve messages by their unique
ids that you had used before.</p>
<h1 align="left">Messages</h1>
<p align="left">Messages in a mailbox can be denoted in one of two ways: message
sequence number or unique id. </p>
<p align="left">The <em>message sequence number</em> is the normal way. The messages
in a mailbox are numbered from 1 to N where N is the number of messages in the mailbox.
There are never any gaps in the sequence numbers. If you tell <strong>imap</strong>
to delete messages 3,4 and 5 then it will return a value telling you the it has deleted
messages 3,3 and 3. This is because when you deleted message 3, message 4 became the
new message 3 just before it was deleted and then message 5 became message 3 just before
it was deleted.</p>
<p align="left">A <em>unique id </em>of a message is a number associated with a message
that is unique only within a mailbox. As long as the uidvalidity value of a
mailbox doesn't change, the unique ids used in deleted messages will never be reused for
new messages. </p>
<h1 align="left">Flags</h1>
<p align="left">A flag is a symbol denoting that a message or mailbox has a certain
property. We use keywords in Lisp to denote flags. There are two
kinds of flags - System and User flags. System flags begin with the backslash
character, which is an unfortunate design decision since that means that in Lisp we
have to remember to use two backslashes (e.g. <strong>:\\deleted</strong>).
A subset of the flags can be stored permanently in the mailbox with the
messages. When a connection is made to an <strong>imap</strong> server it will
return the list of flags and permanent flags (and these are stored in the mailbox object
returned for access by the program). If the list of permanent flags includes <strong>:\\*</strong>
then the program can create its own flag names (not beginning with a backslash) and can
store them permanently in messages.</p>
<p align="left">Some of the important system flags are:</p>
<ul>
<li><p align="left"><strong>:\\seen</strong> - this means that the message has been read
(a <strong>fetch-letter</strong> has been done that includes the content of the
message, not just its headers)</p>
</li>
<li><p align="left"><strong>:\\deleted </strong>- the message will be deleted the next time
an <strong>expunge-mailbox</strong> or <strong>close-mailbox</strong> is done.</p>
</li>
<li><p align="left"><strong>:\\recent </strong>- this is the first session to have been
notified about this message being present in the mailbox.</p>
</li>
</ul>
<p align="left"> </p>
<h1 align="left">Connecting to the server</h1>
<p align="left"> </p>
<p align="left"><font face="Courier New">(<strong>make-imap-connection host &key user
password port timeout)</strong></font></p>
<p align="left">This creates a connection to the <strong>imap</strong> server on machine <strong>host</strong>
and logs in as <strong>user </strong>with password <strong>password. </strong>The
<strong>port</strong> argument defaults to143, which is the port on which the <strong>imap</strong>
server normally listens. The <strong>timeout</strong> argument defaults
to 30 (seconds) and this value is used to limit the amount of time this imap interface
code will wait for a response from the server before giving up. In
certain circumstances the server may get so busy that you see timeout errors signaled in
this code. In that case you should specify a larger timeout when connecting. </p>
<p align="left">The <strong>make-imap-connection</strong> function returns a <strong>mailbox</strong>
object which is then passed to other functions in this interface. From this
one connection you can access all of the mailboxes owned by <strong>user</strong>.</p>
<p align="left">After the connection is established a mailbox is <strong>not</strong>
selected. In this state attempting to execute message access functions may
result in cryptic error messages from the <strong>imap</strong> server that won't tell you
what you need to know -- that a mailbox is not selected. Therefore be sure to
select a mailbox using <strong>select-mailbox</strong> shortly after connecting.</p>
<p align="left"> </p>
<p align="left"> </p>
<p align="left"><strong><font face="Courier New">(close-connection mailbox)</font></strong></p>
<p align="left">This sends a <strong>logout</strong> command to the <strong>imap</strong>
server and then closes the socket that's communicating with the <strong>imap</strong>
server. <strong>mailbox </strong>is the object returned by <strong>make-imap-connection.</strong>
This does <em>not</em> close the currently select mailbox before logging out,
thus messages marked to be deleted in the currently selected mailbox will <em>not</em> be
removed from the mailbox. Use <strong>close-mailbox</strong> or <strong>expunge-mailbox</strong>
before calling this <strong>close-connection</strong> to ensure that messages to be
deleted are deleted.</p>
<p align="left"> </p>
<p align="left"> </p>
<h1 align="left">Mailbox manipulation</h1>
<p align="left">These functions work on mailboxes as a whole. The <strong>mailbox</strong>
argument to the functions is is the object returned by <strong>make-imap-connection.
</strong>If a return value isn't specified for a function then the return value
isn't important - if something goes wrong an error will be signaled.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(select-mailbox mailbox name)</strong></font></p>
<p align="left">makes the mailbox named by the string <strong>name</strong> be the current
mailbox and store statistics about that mailbox in the <strong>mailbox</strong> object
where they can be retrieved by the accessors described below. The
selected mailbox is the source for all message manipulation functions.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(create-mailbox mailbox name)</strong></font></p>
<p align="left">creates a new mailbox with the given <strong>name</strong>. It
is an error if the mailbox already exists. If you want to create a mailbox in a
hierarchy then you should be sure that it uses the correct hierarchy separator character
string (see <strong>mailbox-separator)</strong>. You do <strong>not</strong>
have to create intermediate levels of the hierarchy yourself -- just provide the
complete name and the <strong>imap</strong> server will create all necessary levels.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(delete-mailbox mailbox name)</strong></font></p>
<p align="left">deletes the mailbox with the given name.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(rename-mailbox mailbox old-name
new-name)</strong></font></p>
<p align="left">changes the name of mailbox <strong>old-name</strong> to <strong>new-name</strong>.
It's an error if <strong>new-name</strong> already exists. There's a special
behavior if <strong>old-name</strong> is "inbox". In this case all of the
messages in "inbox" are moved to <strong>new-name </strong>mailbox, but the
"inbox" mailbox continues to exist. Note: The <strong>imap </strong>server
supplied with Linux does <strong>not</strong> support this special behavior of renaming
"inbox".</p>
<p align="left"> </p>
<p align="left"><strong><font face="Courier New">(mailbox-list mailbox &key reference
pattern)</font></strong></p>
<p align="left">returns a list of items describing the mailboxes that match the arguments.
The <strong>reference</strong> is the root of the hierarchy to
scan. By default is is the empty string (from which all mailboxes are reachable).
The <strong>pattern </strong>is a string matched against all mailbox
names reachable from <strong>reference. </strong>There are two special characters allowed
in the <strong>pattern: </strong>Asterisk (*) matches all characters including
hierarchy delimiters. Percent (%) matches all characters but not the hierarchy
delimiter. Thus</p>
<p align="center"><font face="Courier New">(mailbox-list mailbox :pattern "*")</font></p>
<p align="left">returns a list of all mailboxes at all depths in the hierarchy.
</p>
<p align="left">The value returned is a list of lists, but we've created the <strong>mailbox-list
</strong>struct definition in order to make accessing the parts of the inner lists
easier. The accessors for that structure are:</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-list-flags mailbox-list) </strong></font></p>
<p align="left">returns the flags describing this entry. The most important
flag to check is <strong>:\\noselect</strong> as this specifies that this is not a mailbox
but instead just a directory in the hierarchy of mailboxes. The flag <strong>:\\noinferiors</strong>
specifies that you can't create a hierarchical mailbox name with this as a prefix.
This flag is often associated with the special mailbox "inbox".</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-list-separator mailbox-list)</strong></font></p>
<p align="left">returns a string containing the characters used to separate names in a
hierarchical name.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-list-name mailbox-list)</strong></font></p>
<p align="left">returns the name of the mailbox or directory (see mailbox-list-flags to
determine which it is).</p>
<p align="left"> </p>
<h1 align="left">Message manipulation</h1>
<p align="left">These functions work with the messages in the currently selected mailbox.
The <strong>mailbox</strong> argument is the object returned by <strong>make-imap-connection.</strong>
The <strong>messages</strong> argument is either a number (denoting a single
message), or is the list <strong>(:seq N M) </strong>denoting messages <strong>N</strong>
through <strong>M, </strong>or is a list of numbers and <strong>:seq </strong>forms
denoting the messages specified in the list.</p>
<p align="left"> </p>
<p align="left">(<font face="Courier New"><strong>alter-flags mailbox messages &key
flags add-flags remove-flags silent uid)</strong></font></p>
<p>changes the flags of the messages in the specified way. Exactly one of <strong>flags,
add-flags</strong>, and <strong>remove-flags</strong> must be specified. <strong>flags</strong>
specifies the complete set of flags to be stores in the <strong>messages</strong> and the
other two add or remove flags. If <strong>uid</strong> is true then <strong>messages</strong>
will be interpreted as unique ids rather than message sequence numbers.
Normally <strong>alter-flags</strong> returns a data structure
that describes the state of the flags after the alternation has been done. This data
structure can be examined with the <strong>fetch-field</strong> function.
If <strong>silent</strong> is true then this data structure won't be created
thus saving some time and space.</p>
<p>Removing a message from a mailbox is done by adding the <strong>:\\deleted</strong>
flag to the message and then either calling <strong>close-mailbox </strong>or <strong>expunge-mailbox.</strong></p>
<p> </p>
<p><font face="Courier New"><strong>(close-mailbox mailbox)</strong></font></p>
<p>permanently removes all messages flagged as <strong>:\\deleted</strong> from the
currently selected mailbox and then un-selects the currently selected mailbox. After
this command has finished there is no currently selected mailbox.</p>
<p align="left"> </p>
<p align="left"><strong><font face="Courier New">(copy-to-mailbox mailbox messages
destination &key uid)</font></strong></p>
<p align="left">copies the specified <strong>messages </strong>from the currently selected
mailbox to the mailbox named <strong>destination</strong> (given as a string). The
flags are copied as well. The destination mailbox must already exist. The messages
are <strong>not</strong> removed from the selected mailbox after the copy .If <strong>uid</strong>
is true then the <strong>messages</strong> are considered to be unique ids rather than
message sequence numbers. </p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(delete-letter mailbox messages &key
expunge uid</strong></font>)</p>
<p align="left">Mark the <strong>messages</strong> for deletion and then remove them
permanently (using <strong>expunge-mailbox</strong>) if <strong>expunge</strong> is true.
<strong>expunge </strong>defaults to true. If <strong>uid</strong>
is true then the message numbers are unique ids instead of messages sequence numbers.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(expunge-mailbox mailbox)</strong></font></p>
<p align="left">permanently removes all messages flagged as <strong>:\\deleted</strong>
from the currently selected mailbox. The currently selected mailbox stays
selected.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(fetch-field message part info &key
uid)</strong></font></p>
<p align="left">is used to extract the desired information from the value returned by <strong>fetch-letter</strong>.
With <strong>fetch-letter</strong> you can retrieve a variety of
information about one or more messages and <strong>fetch-field</strong> can search though
that information and return a particular piece of information about a particular
letter. <strong>message</strong> is the message number (it's assumed to be a
message sequence number unless <strong>uid </strong>is true, in which case it's a unique
id). <strong>part </strong>is the type of information desired. It is a
string just as used in the call to <strong>fetch-letter</strong>.</p>
<p align="left"> </p>
<p align="left"><strong><font face="Courier New">(fetch-letter mailbox message &key
uid)</font></strong></p>
<p align="left">Return the complete message, headers and body, as one big string.
This is a combination of <strong>fetch-field</strong> and <strong>fetch-parts</strong>
where the part specification is "body[]".</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(fetch-parts mailbox messages parts
&key uid)</strong></font></p>
<p align="left">retrieves the specified <strong>parts</strong> of the specified <strong>messages.
</strong>If <strong>uid</strong> is true then the <strong>messages</strong>
are considered to be unique ids rather than message sequence numbers.
The description of what can be specified for <strong>parts </strong>is
quite complex and is described in the section below "Fetching a Letter".</p>
<p align="left">The return value from this function is a structure that can be examined
with <strong>fetch-field</strong>.</p>
<p align="left">When the result returned includes an envelope value the following
functions can be used to extract the components of the envelope:</p>
<ul>
<li><p align="left"><font face="Courier New"><strong>envelope-date</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-subject</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-from</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-sender</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-reply-to</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-to</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-cc</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-bcc</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-in-reply-to</strong></font></p>
</li>
<li><p align="left"><font face="Courier New"><strong>envelope-message-id</strong></font></p>
</li>
</ul>
<p align="left"> </p>
<p align="left"> </p>
<p align="left"><strong><font face="Courier New">(noop mailbox)</font></strong></p>
<p align="left">does nothing but remind the <strong>imap</strong> server that this
client is still active, thus resetting the timers used in the server that will
automatically shut down this connection after a period of inactivity. Like all
other commands if messages have been added to the currently selected mailbox, the server
will return the new message count as a response to the <strong>noop</strong> command, and
this can be check using <strong>mailbox-message-count</strong>. </p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(search-mailbox mailbox search-expression
&key uid)</strong></font></p>
<p align="left">return a list of messages in the mailbox that satisfy the<strong>
search-expression. </strong>If <strong>uid</strong> is true then unique ids
will be returned instead of message sequence numbers. See the section
"Searching for messages" for details on the <strong>search-expression</strong>.</p>
<p align="left"> </p>
<h1 align="left">Mailbox Accessors</h1>
<p align="left">The mailbox object contains information about the <strong>imap </strong>server
it's connected to as well as the currently selected mailbox. This information
can potentially be updated each time a request is made to the <strong>imap </strong>server.
The following functions access values from the mailbox object. </p>
<p align="left"><font face="Courier New"><strong>(mailbox-flags mailbox)</strong></font></p>
<p align="left">returns a complete list of flags used in all the messages in this mailbox.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-permanent-flags mailbox)</strong></font></p>
<p align="left">returns a list of flags that can be stored permanently in a message.
If the flag <strong>:\\*</strong> is present then it means that the client can
create its own flags.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-message-count mailbox)</strong></font></p>
<p align="left">returns the number of messages in the currently selected mailbox</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-recent-messages mailbox)</strong></font></p>
<p align="left">returns the number of messages have just arrived in the mailbox.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-separator mailbox)</strong></font></p>
<p align="left">returns the hierarchy separator string for this <strong>imap </strong>server.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-uidnext mailbox)</strong></font></p>
<p align="left">returns the value predicated to be the unique id assigned to the
next message.</p>
<p align="left"> </p>
<p align="left"><font face="Courier New"><strong>(mailbox-uidvalidty mailbox)</strong></font></p>
<p align="left">returns the uidvalidity value for the currently selected mailbox.</p>
<p align="left"> </p>
<p align="left"> </p>
<h1 align="left">Fetching a Letter</h1>
<p align="left">When using <strong>fetch-parts</strong> to access letters, you must
specify the parts of the messages in which you're interested. There are a wide
variety of specifiers, some redundant and overlapping, described in the imap specification
in rfe2060. We'll describe the most common ones here. The specification
is always a string but it may be specified more than one thing by the use of parentheses
in the string, e.g. "(flags envelope)". </p>
<p align="left">The most common specifiers are:</p>
<ul>
<li><p align="left"><strong>body[]</strong> - this returns the full message: headers and
body. You can use <strong>fetch-letter</strong> if you only want this part and
you want to avoid having to call <strong>fetch-field</strong>.</p>
</li>
<li><p align="left"><strong>body[text]</strong> - this returns just the the text of the body
of the message, not the header.</p>
</li>
<li><p align="left"><strong>body</strong> - this returns a list describing the structure of
the message.</p>
</li>
<li><p align="left"><strong>envelope</strong> - this parses the header and returns a list of
information in it. We've defined a set of accessors <strong>(</strong>like<strong>
envelope-xxx</strong>) that allow you to retrieve the envelope information easily.</p>
</li>
<li><p align="left"><strong>flags</strong> - return a list of the flags in the message</p>
</li>
<li><p align="left"><strong>uid</strong> - the unique identifier of the message</p>
</li>
</ul>
<p align="left"> </p>
<p align="left">The result of a <strong>fetch-parts</strong> is a data structure
containing all of the requested information. The <strong>fetch-field</strong>
function is then used to extract the particular information for the particular message.</p>
<p align="left"> </p>
<h1 align="left">Searching for Messages</h1>
<p align="left">.The <strong>imap</strong> server is able to search for messages matching
a search expression. A search-expression is a predicate or one of
these forms:</p>
<ul>
<li><p align="left">(<strong>and</strong> search-expression ...)</p>
</li>
<li><p align="left">(<strong>or</strong> search-expression ...)</p>
</li>
<li><p align="left">(<strong>not</strong> search-expression)</p>
</li>
</ul>
<p align="left">A predicate is </p>
<ul>
<li><p align="left">a number in which case the predicate is true if and only if we're are
considering this message</p>
</li>
<li><p align="left">a <strong>(:seq N M)</strong> expression that is true if we're
considering messages N through M.</p>
</li>
<li><p align="left"><strong>:all</strong> - this predicate is always true</p>
</li>
<li><p align="left"><strong>:answered</strong> - true if the message has the <strong>:\\answered</strong>
flag</p>
</li>
<li><p align="left"><strong>(:bcc "string") </strong>- true if the envelope
structure's bcc field contains this "string".</p>
</li>
<li><p align="left"><strong>(:before date)</strong> - true if the messages internal date is
before this date. The date can either be a string in the rfc822 form (e.g.
"7-Mar-1999") or a lisp universal time.</p>
</li>
<li><p align="left"><strong>(:body "string") </strong>- true if the body of the
message contains "string"</p>
</li>
<li><p align="left"><strong>(:cc "string")</strong> - true if the envelope
structure's cc field contains this "string".</p>
</li>
<li><p align="left"><strong>:deleted</strong> - true if the <strong>:\\deleted</strong> flag
is set for this message</p>
</li>
<li><p align="left"><strong>:draft</strong> - true if the <strong>:\\draft </strong>flag is
set for this message</p>
</li>
<li><p align="left"><strong>:flagged </strong>- true if the <strong>:\\flagged</strong> flag
is set for this message</p>
</li>
<li><p align="left"><strong>(:from "string")</strong> - true if the envelope
structure's from field contains this "string".</p>
</li>
<li><p align="left"><strong>(:header "field" "string")</strong> - true
if the message contains a header named "field" and its value contains
"string".</p>
</li>
<li><p align="left"><strong>(:keyword flag)</strong> - true if the specified flag is set for
this message</p>
</li>
<li><p align="left"><strong>(:larger N)</strong> - true if the rfc822 size of the message is
larger than N.</p>
</li>
<li><p align="left"><strong>:new </strong>- true if the message has the <strong>:\\recent</strong>
flag set but not the <strong>:\\seen </strong>flag.</p>
</li>
<li><p align="left"><strong>:seen </strong>- true if the message has the <strong>:\\seen </strong>flag
set.</p>
</li>
<li><p align="left"><strong>(:sentbefore date)</strong> - true if the message's Date header
is earlier than the given date. See the description of :before for the format of
dates.</p>
</li>
<li><p align="left"><strong>(:senton date)</strong> - true if the message's Date header is
within the specified date.</p>
</li>
<li><p align="left"><strong>(:sentsince date) </strong>- true if the message's Date header
is within or since the given date.</p>
</li>
<li><p align="left"><strong>(:smaller N)</strong> - true if the rfc822 size of the message
is smaller than N</p>
</li>
<li><p align="left"><strong>(:subject "string") </strong>- true if the Subject
header line of the message contains "string"</p>
</li>
<li><p align="left"><strong>(:text "string") </strong>- true if the message's
header or body contains the specified "string"</p>
</li>
<li><p align="left"><strong>(:to "string")</strong> - true if the envelope
structure's to field contains this "string".</p>
</li>
<li><p align="left"><strong>(:uid message-set)</strong> - true if the message is one of the
message denoted by the message set, where the message set describes messages by unique id.</p>
</li>
<li><p align="left"><strong>:unanswered</strong> - true if the message does not have the <strong>:\\answered</strong>
flag set</p>
</li>
<li><p align="left"><strong>:undeleted</strong> - true if the message does not have the <strong>:\\deleted</strong>
flag set</p>
</li>
<li><p align="left"><strong>:undraft </strong>- true if the message does not have the <strong>:\\draft
</strong>flag set.</p>
</li>
<li><p align="left"><strong>:unflagged </strong>- true if the message does not have the <strong>:\\flagged</strong>
flag set.</p>
</li>
<li><p align="left"><strong>(:unkeyword flag)</strong> - true if the message does not have
the specified flag set.</p>
</li>
<li><p align="left"><strong>:unseen </strong>- true if the message does not have the <strong>:\\seen
</strong>flag set.</p>
</li>
</ul>
<p align="left"> </p>
<h1 align="left">Examples</h1>
<p align="left">We show an example of using this interface</p>
<p align="left"> </p>
<p align="left"><strong>Connect to the imap server on the machine holding the email:</strong></p>
<div align="left">
<pre>user(2): (setq mb (make-imap-connection "mailmachine.franz.com"
:user "myacct"
:password "mypasswd"))
#<mailbox::imap-mailbox @ #x2064ca4a></pre>
</div>
<p align="left"> </p>
<p align="left"><strong>Select the inbox, that's where the incoming mail arrives:</strong></p>
<div align="left">
<pre>
user(3): (select-mailbox mb "inbox")
t</pre>
</div>
<p align="left"> </p>
<p align="left"><strong>Check how many messages are in the mailbox:</strong></p>
<div align="left">
<pre>
user(4): (mailbox-message-count mb)
7</pre>
</div>
<p align="left"><strong>There are seven messages at the moment. Fetch the
whole 4th message. We could call (fetch-letter mb 4) here instead and then not have
to call fetch-field later.</strong></p>
<div align="left">
<pre>
user(5): (setq body (fetch-parts mb 4 "body[]"))
((4
("BODY[]" "Return-Path: <[email protected]>
Received: from tiger.franz.com (jkf@tiger [192.132.95.103])
by tiger.franz.com (8.8.7/8.8.7) with SMTP id LAA20261
for <[email protected]>; Mon, 13 Sep 1999 11:36:26 -0700
Date: Mon, 13 Sep 1999 11:36:26 -0700
From: jkf mail tester <[email protected]>
Message-Id: <[email protected]>
message number 5
")))</pre>
</div>
<p align="left"><strong>The value was returned inside a data structure designed to hold
information about one or more messages. In order to extract the particular
information we want we use fetch-field:</strong></p>
<div align="left">
<pre>
user(6): (fetch-field 4 "body[]" body)
"Return-Path: <[email protected]>
Received: from tiger.franz.com (jkf@tiger [192.132.95.103])
by tiger.franz.com (8.8.7/8.8.7) with SMTP id LAA20261
for <[email protected]>; Mon, 13 Sep 1999 11:36:26 -0700
Date: Mon, 13 Sep 1999 11:36:26 -0700
From: jkf mail tester <[email protected]>
Message-Id: <[email protected]>
message number 5
"</pre>
</div>
<p align="left"><strong>We use the search function to find all the messages containing the
word blitzfig. It turns out there is only one. We then extract the contents of
that message.</strong></p>
<div align="left">
<pre>
user(7): (search-mailbox mb '(:text "blitzfig"))
(7)
user(8): (fetch-field 7 "body[]" (fetch-letter mb 7 "body[]"))
"Return-Path: <[email protected]>
Received: from main.verada.com (main.verada.com [208.164.216.3])
by tiger.franz.com (8.8.7/8.8.7) with ESMTP id NAA20541
for <[email protected]>; Mon, 13 Sep 1999 13:37:24 -0700
Received: from main.verada.com (IDENT:jkf@localhost [127.0.0.1])
by main.verada.com (8.9.3/8.9.3) with ESMTP id NAA06121
for <[email protected]>; Mon, 13 Sep 1999 13:36:54 -0700
Message-Id: <[email protected]>
Subject: s test
Date: Mon, 13 Sep 1999 13:36:54 -0700
From: jkf <[email protected]>
secret word: blitzfig
ok?
"</pre>
</div>
<p align="left"><strong>We've been using message sequence numbers up to now.
The are the simplest to use but if you're concerned with keeping track of messages when
deletions are being done then using unique id's is useful. Here we do the
above search example using uids:</strong></p>
<div align="left">
<pre>
user(9): (search-mailbox mb '(:text "blitzfig") :uid t)
(68)
user(10): (fetch-field 68 "body[]" (fetch-letter mb 68 "body[]" :uid t) :uid t)
"Return-Path: <[email protected]>
Received: from main.verada.com (main.verada.com [208.164.216.3])
by tiger.franz.com (8.8.7/8.8.7) with ESMTP id NAA20541
for <[email protected]>; Mon, 13 Sep 1999 13:37:24 -0700
Received: from main.verada.com (IDENT:jkf@localhost [127.0.0.1])
by main.verada.com (8.9.3/8.9.3) with ESMTP id NAA06121
for <[email protected]>; Mon, 13 Sep 1999 13:36:54 -0700
Message-Id: <[email protected]>
Subject: s test
Date: Mon, 13 Sep 1999 13:36:54 -0700
From: jkf <[email protected]>
secret word: blitzfig
ok?
"</pre>
</div>
<p align="left"><strong>We'll delete that letter with the secret word and then note that
we have only six messages in the mailbox.</strong></p>
<div align="left">
<pre>
user(11): (delete-letter mb 68 :uid t)
(7)
user(12): (mailbox-message-count mb)
6</pre>
</div>
<p align="left"><strong>Now we assume that a bit of time has passed and we want to see if
any new messages have been delivered into the mailbox. In order to find out we
have to send a command to the imap server since it will only notify us of new messages
when it responds to a command. Since we have nothing to ask the imap server to
do we issue the noop command, which does nothing on the server.</strong></p>
<div align="left">
<pre>
user(13): (noop mb)
nil
user(14): (mailbox-message-count mb)
7</pre>
</div>
<p align="left"><strong>The server told us that there are now 7 messages in the inbox, one
more than before. Next we create a new mailbox, copy the messages from the inbox to
the new mailbox and then delete them from the inbox. Note how we use the :seq form
to specify a sequence of messages.</strong></p>
<div align="left">
<pre>
user(15): (create-mailbox mb "tempbox")
t
user(18): (let ((count (mailbox-message-count mb)))
(copy-to-mailbox mb `(:seq 1 ,count) "tempbox")
(delete-letter mb `(:seq 1 ,count)))
(1 1 1 1 1 1 1)
user(19): (mailbox-message-count mb)
0</pre>
</div>
<p align="left"><strong>When we're done there are 0 messages in the currently selected
mailbox, which is inbox. We now select the maibox we just created and see that the
messages are there.</strong></p>
<div align="left">
<pre>
user(22): (select-mailbox mb "tempbox")
t
user(23): (mailbox-message-count mb)
7</pre>
</div>
<p align="left"><strong>Finally we shut down the connection. Note that imap
servers will automatically shut down a connection that's been idle for too long (usually
around 10 minutes). When that happens, the next time the client tries to use an imap
function to access the mailbox an error will occur. There is nothing that can
be done to revive the connection however it is important to call close-imap-connection on
the lisp side in order to free up the resources still in use for the now dead connection.</strong></p>
<div align="left">
<pre>
user(24): (close-connection mb)
t
</pre>
</div>
<p align="left"> </p>
<h1><a name="pop"></a>The Pop interface</h1>
<p>The <strong>pop</strong> protocol is a very simple means for retrieving messages from a
single mailbox. The functions in the interface are:</p>
<p> </p>
<p align="left"><font face="Courier New">(<strong>make-pop-connection host &key user
password port timeout)</strong></font></p>
<p align="left">This creates a connection to the <strong>pop</strong> server on machine <strong>host</strong>
and logs in as <strong>user </strong>with password <strong>password. </strong>The
<strong>port</strong> argument defaults to 110, which is the port on which the <strong>pop</strong>
server normally listens. The <strong>timeout</strong> argument defaults
to 30 (seconds) and this value is used to limit the amount of time this pop interface code
will wait for a response from the server before giving up. In certain
circumstances the server may get so busy that you see timeout errors signaled in this
code. In that case you should specify a larger timeout when connecting. </p>
<p>The value returned by this function is a <strong>mailbox</strong> object. You can
call <strong>mailbox-message-count</strong> on the <strong>mailbox</strong> object to
determine how many letters are currently stored in the mailbox.</p>
<p> </p>
<p><font face="Courier New"><strong>(close-connection mb)</strong></font></p>
<p>Disconnect from the pop server. All messages marked for deletion will be deleted.</p>
<p> </p>
<p><strong><font face="Courier New">(delete-letter mb messages)</font></strong></p>
<p>Mark the specified <strong>messages</strong> for deletion. <strong>mb </strong>is
the mailbox object returned by <strong>make-pop-connection</strong>. The messages
are only marked for deletion. They are not removed until a <strong>close-connection</strong>
is done. If the connection to the <strong>pop</strong> server is broken before a <strong>close-connection</strong>
is done, the messages will <strong>not</strong> be deleted and they will no longer be
marked for deletion either.</p>
<p><strong>messages</strong> can either be a message number, a list of the form <strong>(:seq
N M)</strong> meaning messages <strong>N </strong>through <strong>M </strong>or it can be
a list of message numbers and/or <strong>:seq </strong>specifiers. The
messages in a mailbox are numbered starting with one. Marking a message for deletion
does not affect the numbering of other messages in the mailbox.</p>
<p> </p>
<p><font face="Courier New"><strong>(fetch-letter mb message)</strong></font></p>
<p>Fetch from the pop server connection <strong>mb</strong> the letter numbered <strong>message</strong>.
The letters in a mailbox are numbered starting with one. The entire
message, including the headers, is returned as a string. It is an
error to attempt to fetch a letter marked for deletion.</p>
<p> </p>
<p><font face="Courier New"><strong>(make-envelope-from-text text)</strong></font></p>
<p><strong>text</strong> is a string that is the first part of a mail message, including
at least all of the headers lines and the blank line following the headers. This
function parses the header lines and return an <strong>envelope</strong> structure