roundcube cannot send emails - relay access denied after migrating to new server

I am having an issue with roundcube webmail client not being able to send emails after migration to new server. It worked perfectly on old server. I am getting:

SMTP Error (454): Failed to add recipient 4.7.1 Relay access denied).



still can't get this going?

Howdy -- out of curiosity, are other clients able to send email? For example, can you send email using Outlook or Thunderbird?

I'm curious if that's perhaps a symptom of TLS not setup or working.

Hi, I don't let anyone send mail through my server - only my webmail clients. It was working ok on the old server?

ok, fixed this one too. For some reason CentOS 7 has a setting that doesn't like the 'localhost' setup in the smtp area of If you remove the 'localhost' and leave it as '' then roundcube will use PHP Mail instead - which works.

Ah, sounds like you figured that out as well! Was this RoundCube installation migrated from your other server? Or was it a new installation?