I have a hosting server, configured as per the Perfect Setup (Opensuse 10), with ISPConfig installed. Everything seems to be working - uptime has been over a month, now, with the only problems I've had so far being domain registration hiccups which have nothing to do with my server. However, one of my customers is testing a web order form, and I've run into a problem: while emails incoming from outside servers work fine, local deliveries don't seem to be using email aliases properly. Eg. Username: example.admin Primary email: firstname.lastname@example.org Alias: email@example.com If I send an email to firstname.lastname@example.org from outside, it works without a problem. If I send it from an another domain also hosted on the site, email@example.com, it bounces back with the following error: I checked all the threads on Postfix problems I could, and the following have already been ruled out: - The server's FQDN is main.example.com - The $myhostname parameter in main.cf is main.example.com - main.example.com is not used as a virtual domain for any email or web services. www.example.com and example.com are, however. - All DNS entries are correct. Again, outside email works fine with the alias rewriting. - alias_maps = hash:/etc/aliases - virtual_maps = hash:/etc/postfix/virtusertable - mydestination = /etc/postfix/local-host-names - firstname.lastname@example.org and email@example.com are both present in /etc/postfix/virtusertable and point to example.admin - example.com is listed in /etc/postfix/local-host-names Any help would be greatly appreciated!