Cancel ICS file corrupted on Office 365

[bashirmurtaza93]

There seems to be a recent issue with Office 365 when sending out cancellation Ical emails.
The main issue is that within the core code, when Ical is set, it's setting the method header to REQUEST. However, if you're sending a cancellation, you would need to set the method to CANCEL instead.

Is there anyway within PHPMailer to set this?

To be clear i'm referring to this snippet

   case 'alt':
   $body .= $mimepre;
   $body .= $this->getBoundary($this->boundary[1], $altBodyCharSet, 'text/plain', $altBodyEncoding);
   $body .= $this->encodeString($this->AltBody, $altBodyEncoding);
   $body .= $this->LE . $this->LE;
   $body .= $this->getBoundary($this->boundary[1], $bodyCharSet, 'text/html', $bodyEncoding);
   $body .= $this->encodeString($this->Body, $bodyEncoding);
   $body .= $this->LE . $this->LE;
   if (!empty($this->Ical)) {
      $body .= $this->getBoundary($this->boundary[1], '', 'text/calendar; method=REQUEST, ''); //NEED TO CHANGE THIS TO CANCEL
      $body .= $this->encodeString($this->Ical, $this->Encoding);
      $body .= $this->LE . $this->LE;
      
     }
    $body .= $this->endBoundary($this->boundary[1]);
    break;

[Synchro]

Not at the moment, no. I guess the best way to handle this would be to inspect the contents of the Ical property and figure out what method it should be using. Ical is generally very difficult to support because pretty much every client does not conform with RFCs (for example, Outlook should not be relying on this header at all - the status value is visible inside the Ical data), and their inconsistency makes it mostly impossible to create an ical email that works everywhere.

[bashirmurtaza93]

Thanks for the quick response! I'll investigate further, and if I come up with a workaround to solve this issue, i'll post it here. Thanks!

[GeorgeWells]

I hit this problem and found a way to get it working. Use addStringAttachment to attach the ical and specify the method in 4th parameter i.e.

$mail->addStringAttachment($ical, 'ical.ics', 'base64', 'text/calendar; method=CANCEL');

[Synchro]

Nice idea, @GeorgeWells. That will work for some clients but not all - there seems to be a fairly even split between those clients that want ICS files as attachments vs those that expect it as part of a multipart/alternative structure. It seems to be impossible to make it work everywhere. See #175 for more discussion on this.

[puhr-mde]

We came up with the same Bug. The reasen is the static header 'content-type' for multipart in function createBody(). In cases of 'alt' and 'alt_attach' with !empty($this->Ical) the method will always been set to 'REQUEST'. By setting the method to canel hardcoded in my testcase, the cancellation was successfull. Needed BugFix would be a parameter oder kind of magic to set the method correctly.

if (!empty($this->Ical)) { $body .= $this->getBoundary($this->boundary[2], '', 'text/calendar; method=REQUEST', ''); $body .= $this->encodeString($this->Ical, $this->Encoding); }

[Synchro]

Closed via #1842