I've recently set up a mail-server using Postfix, Dovecot and mySQL. Everything works fine except that I can't send email to other mailservers say Google. I get the following error:
Aug 15 11:14:27 server postfix/cleanup: warning: mysql:/etc/postfix/mysql_virtual_alias_domainaliases_maps.cf lookup error for "firstname.lastname@example.org" Aug 15 11:14:27 server postfix/cleanup: warning: 82B3F22073: virtual_alias_maps map lookup problem for email@example.com -- message not accepted, try again later
I think that postfix tries to somehow authenticate all outgoing email addresses using virtual_alias table, but I can't figure which settings I should change to fix this. I tried Mailx command using ssh session on mailserver and also from macOSX mail client, which both were unsuccessful with the same error.
BTW I used the guide in: https://www.exratione.com/2014/05/a-mailserver-on-ubuntu-1404-postfix-dovecot-mysql/