After upgrading CiviCRM from 4.6 to 4.7.14 I was not able to send (test) emails via SMTP. I got the following error:
authentication failure [SMTP: STARTTLS failed (code: 220, response: 2.0.0 Ready to start TLS)]
After replacing some code in
/packages/Net/SMTP.php like Matt suggested I'm now receiving the error:
authentication failure [SMTP: Invalid response code received from SMTP server while sending email. This is often caused by a misconfiguration in Outbound Email settings. Please verify the settings at Administer CiviCRM >> Global Settings >> Outbound Email (SMTP). (code: 535, response: 5.7.8 Error: authentication failed: authentication failure)]
Dec 21 11:19:55 rs0815 postfix/smtpd: warning: SASL authentication failure: client response doesn't match what we generated Dec 21 11:19:55 rs0815 postfix/smtpd: warning: rs0815.rs.example.de[188.8.131.52]: SASL DIGEST-MD5 authentication failed: authentication failure
I doesn't make a difference if I use PHP 5.5 or 5.6.
Any idea what could cause this?