Roundcube: SMTP server does not support authentication

When I try to send a letter from Roundcube I get the following error:

This can happen if Postfix doesn’t allow authentication from a localhost where Roundcube resides or if authentication scheme is wrong.

Update the /etc/postfix/main.cf :

Specify “mynetworks_style = host” when Postfix should “trust” localhost.

Next, in Roundcube’s settings (default.inc.cfg) make sure you specified correct authentication scheme. In my case it’s STARTTLS. As description states:

So I added “tls://” in front of FQDN of my SMTP server:

And that fixed Authentication failure: SMTP server does not support authentication (Code: )) error.

After that I had to fix one more error as described here.

Good luck!

Want me to do this for you? Drop me a line: itgalaxyzzz {at} gmail [point] com