Hi guys, I really tried a lot and did so much research, but I'm to stupid to do what i need. I have an external mailserver. This mailserver accepts mails for the domain example1.com only. Every other domain is rejected. Now I really need a domainalias (example2.com) for the first domain. This cant be done with the other mailserver. So I tried zu following: setting MX-Records to my server where ispconfig is running. Configuring and relay-receiver, E-Mail-Transport and content-filter. Relay-Receiver receives the mail, then the filter replaces the domain and then the transport redirects the mail to the right server. Receiving and redirecting to the other server working nice. But replacing the domain wont work Filter: Header-Filter Regex: /@example1.com/ Data: @example2.com Action: Replace Whats my fault and what i need to do, to get this working? Watching the manual I bought for ispconfig, didnt help me.