When I try o send emails with those outlooks gives me an error 17895. I have tested: port 25 same issue, 485 same issue, 587 same issue, I had the Microsoft engineers for a day looking at it with no luck, I have search 4 easy for any hint with no luck, and asked help for this for support in my server with no luck.
The questions is any other mail apps work perfectly well, if I use other linux server for sending with those messages in outlook (my Channel) works perfect.
Can you help?
Mail log
Nov 29 07:52:40 localhost postfix/submission/smtpd[23338]: connect from unknown[88.98.aaa.aaa]
Nov 29 07:52:40 localhost postfix/submission/smtpd[23338]: lost connection after EHLO from unknown[88.98.aaa.aaa]
Nov 29 07:52:40 localhost postfix/submission/smtpd[23338]: disconnect from unknown[88.98.aaa.aaa] ehlo=2 starttls=1 commands=3
Nov 29 07:52:40 localhost postfix/submission/smtpd[24749]: connect from unknown[88.98.aaa.aaa]
Nov 29 07:52:41 localhost postfix/submission/smtpd[24749]: lost connection after EHLO from unknown[88.98.aaa.aaa]
Nov 29 07:52:41 localhost postfix/submission/smtpd[24749]: disconnect from unknown[88.98.aaa.aaa] ehlo=2 starttls=1 commands=3
Nov 29 07:52:41 localhost postfix/submission/smtpd[23338]: connect from unknown[88.98.aaa.aaa]
Outlook on POP + SSL - Unable to sign in. Check your credentials and try again.
Outlook on POP - SSL - Unable to sign in. Check your credentials and try again.
Mail App OSX
POP3 Automatic config - OK
Warning - Mail cannot send your password securely to the server. You can continue without a secured password, which could put your password at risk. But in the final works.
Thunderbird for OSX
POP3 connection OK
Warning about insecure mail connection on both IMAP & POP; SMTP ok
Definitely it’s a specific problem with Outlook 365 on POP3.
Please investigate and come with a solution.
I just realised that our /etc/dovecot/dovecot.conf doesn’t have the include to read the conf.d files.
Numeriku was right, put the “auth_mechanisms = plain login” in /etc/dovecot/dovecot.conf
Anyway, that should be included by default in the install of CP to avoid issues