SMTP error

[hede]

Am Mon, 1 Jun 2015 22:16:01 -0500 schrieb Tim Apple <timapple at outlook.com>:

> SMTP Error (454): Authentication failed.

Where do you see this message? (Roundcube, Postfix log, your local email client, ...)

I.e. is your email client (roundcube / some desktop client / etc.) trying to deliver mail to kolab/postfix or is kolab/postfix trying to deliver mail to a remote smtp server / smarthost?

If this error 454 is from postfix, it means: TLS not available due to local problem

Which Kolab Version are you using? There was a bug with Kolab 3.1 back in 2013. See:
http://lists.kolab.org/pipermail/users/2013-December/016132.html

Did you configure postfix to use some tls certs? (smtpd_use_tls = yes, smtpd_tls_key_file = ...)

Search your logs for more informations (e.g. restart postfix, search for tls/ssl related warnings in /var/log/mail.log, try to send a message, search additional logs, etc.).

Regards
hede

PS: With Debian / Ubuntu the log is /var/log/mail.log, with Red Hat / CentOS it's /var/log/maillog AFAIK