main.cf: virtual_alias_maps = proxy:mysql:/etc/postfix/mysql/virtual_alias_maps.cf
master.cf: smtpd pass - - n - 500 smtpd [no -o parameter=value] With these two lines, the Postfix SMTP server will not reject recipients with "user unknown" when their address is listed in virtual_alias_maps. As long as the virtual_alias_maps lookup produces a result, the SMTP server will accept the mail. It does not matter what the lookup result looks like. This is in fact a known limitation of Postfix; it does not try to find out if the result address should be rejected as "user unknown". If your Postfix server behaves in a different manner, then it has been modified. Wietse