Hello Guys, i recently settet up my new Hosting servers. I have on Customer, that has an own Mailserver, but my Servers handles mail first, then relaying to specific IP+Port -> only my IPs are allowed in customers Firewall. with my old setup, i had one ispconfig server, and one server mit normal postfix with differen transports like this: Old Setup was for example: Customers-IP: 1.2.3.4 Customers Mailserver Port: 825 My old ISPConfig Server: Relay recipient: @customerdomain.tld Mail Route: @customerdomain.tld -> smtp:[1.2.3.4]:825 Old Postfix Relay recipient: @customerdomain.tld Mail Route: @customerdomain.tld -> smtp:[1.2.3.4]:826 second Mailserver delivers to 826 instead of 825 becouse customers firewall can only accept IP+port Combinations (dont ask my why someone sell this crap ) Problem with mirror setup is now, when is set up a Mail routing like this: My new ISPConfig Server: Relay recipient: @customerdomain.tld Mail Route: @customerdomain.tld -> smtp:[1.2.3.4]:825 is the same config for mirror, what couses problems. Has anyone hints or ideas how i can achive that second server will relay mails to 826 instead of 825: following ideas until now: - Manual preparation of mail_transport table -> maybe 2nd entry with second server? - add Custom Transport config on Postfix to override ispconfig? custom db table mail_transport_custom in dbispconig, REPLACE INTO Records from mail_transport to new table, then add custom Route and change postfix to use new custom table?! maybe there are possibilitys with less "crafting" thx guys!
i have tested this setup now and recognized that it is working without rewrite, but why? maybe is this related to ipv4 ip rewrite in ISPconfig? i have no idea why server 2 is able to relay mails through its own ip address and port 825 becouse in firewall is only 826 is allowed?! i tryed to reach the ports 825 and 826 from other endpoints and there are not reachable. little bit strange for me at the moment why it works
