GMail SMTP connect() failed

[mitsus]

Hi all,
i'm try to send eamil using gmail with my raspberry Pi (it it into my Home Lan).
I try to use exactly this example https://github.com/PHPMailer/PHPMailer/blob/master/examples/gmail.phps, but i've these errors:

   # php -q test_gmail.php 
   Connection: opening to smtp.gmail.com:587, timeout=300, options=array (  &#039;ssl&#039; =&gt;   array (    &#039;verify_peer&#039; =&gt; false,    &#039;verify_peer_name&#039; =&gt; false,    &#039;allow_self_signed&#039; =&gt; true,  ),)<br>
   Connection: opened<br>
   SERVER -&gt; CLIENT: 220 smtp.gmail.com ESMTP uq5sm4060328wjc.3 - gsmtp<br>
   CLIENT -&gt; SERVER: EHLO mauNone<br>
   SERVER -&gt; CLIENT: 250-smtp.gmail.com at your service, [91.213.153.133]250-SIZE 35882577250-8BITMIME250-STARTTLS250-ENHANCEDSTATUSCODES250-PIPELINING250-     CHUNKING250 SMTPUTF8<br>
   CLIENT -&gt; SERVER: STARTTLS<br>
   SERVER -&gt; CLIENT: 220 2.0.0 Ready to start TLS<br>
   CLIENT -&gt; SERVER: EHLO mauNone<br>
   SERVER -&gt; CLIENT: 250-smtp.gmail.com at your service, [91.213.153.133]250-SIZE 35882577250-8BITMIME250-AUTH LOGIN PLAIN XOAUTH2 PLAIN-CLIENTTOKEN OAUTHBEARER  XOAUTH250-ENHANCEDSTATUSCODES250-PIPELINING250-CHUNKING250 SMTPUTF8<br>
   CLIENT -&gt; SERVER: AUTH LOGIN<br>
   SERVER -&gt; CLIENT: 334 VXNlcm5hbWU6<br>
   CLIENT -&gt; SERVER: bWl0c3VzZGV2QGdtYWlsLmNvbQ==<br>
   SERVER -&gt; CLIENT: 334 UGFzc3dvcmQ6<br>
   CLIENT -&gt; SERVER: OW1hZDltYXg5<br>
   SERVER -&gt; CLIENT: 534-5.7.14 &lt;https://accounts.google.com/ContinueSignIn?sarp=1&amp;scc=1&amp;plt=AKgnsbtHB534-5.7.14 8ji9BpiKRFNEvWjl8WaaMaJUOJrfa3PLsUT9r_mhnYWYuE_ryBHUfyiCIgZv1W2z45QaZB534-5.7.14 n5urMjr5r8Xbegf5zNbgtI2ShYag95Q0AxSfc_1rzHq0793eETS5jTbQA6YG8Skvc2I8Lu534-5.7.14 qdIkuzdjGZYaxTl10kXU08P0DUxvaEDtMCV6VXwf02_29LpN3g6O33WcHYQz0p7D8SvV3y534-5.7.14 GSZO9YztI7FHgS18R0lR5Vcw4xdw&gt; Please log in via your web browser and534-5.7.14 then try again.534-5.7.14  Learn more at534 5.7.14  https://support.google.com/mail/answer/78754 uq5sm4060328wjc.3 - gsmtp<br>
   SMTP ERROR: Password command failed: 534-5.7.14 &lt;https://accounts.google.com/ContinueSignIn?sarp=1&amp;scc=1&amp;plt=AKgnsbtHB534-5.7.14 8ji9BpiKRFNEvWjl8WaaMaJUOJrfa3PLsUT9r_mhnYWYuE_ryBHUfyiCIgZv1W2z45QaZB534-5.7.14 n5urMjr5r8Xbegf5zNbgtI2ShYag95Q0AxSfc_1rzHq0793eETS5jTbQA6YG8Skvc2I8Lu534-5.7.14 qdIkuzdjGZYaxTl10kXU08P0DUxvaEDtMCV6VXwf02_29LpN3g6O33WcHYQz0p7D8SvV3y534-5.7.14 GSZO9YztI7FHgS18R0lR5Vcw4xdw&gt; Please log in via your web browser and534-5.7.14 then try  again.534-5.7.14  Learn more at534 5.7.14  https://support.google.com/mail/answer/78754  uq5sm4060328wjc.3 - gsmtp<br>
   SMTP Error: Could not authenticate.<br>
   CLIENT -&gt; SERVER: QUIT<br>
   SERVER -&gt; CLIENT: 221 2.0.0 closing connection uq5sm4060328wjc.3 - gsmtp<br>
   Connection: closed<br>
   SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting<br>
   Mailer Error: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

So..i've read https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting, but i can not use oauth authentication, because my device (Raspberry pi) is into my LAN and i'm not able to specify to google an public host name.

My question is how can i solve the problem? I don't understand how other emails client as Thunderbird, Outlook, ecc can set correctly an gmail account without oauth authentication.

Thanks a lot and best Regards

[Synchro]

So, like the troubleshooting guide says, enable access for 'less secure apps' in your gmail account. The same applies to other clients that do not support XOAUTH2. Apple Mail on OS X and iOS supports XOAUTH2 with gmail, but I don't know about others.

[Sathiesh]

Is it necessary to turn on the less secure apps of my gmail account? why I'm asking this means am trying to do send email in production.
I tried without turn on my less secure apps of my email account, I get error like below
SMTP ERROR: Password command failed: 534-5.7.14
SMTP Error: Could not authenticate.

[Synchro]

Read the troubleshooting guide to help diagnose your problem. It's not necessary to enable less secure apps if you use XOAUTH2 authentication - look at the wiki for more info.