On 22.09.24 15:35, Christian Schulte wrote: > On 22.09.24 12:16, Philipp wrote: >> [2024-09-22 09:39] Christian Schulte <c...@schulte.it> >>> >>> [snip] >>> >> >> There are several problems: >> >> First of all it's not that simple to know for wich domains your server >> is reponsible for. Yes you could check MX recourds and lookup the A >> and AAAA records. But a negativ match isn't true, because you might >> be a MX later in the chain or run behind some NAT. >> >> Next when you have a server for outgoing mails and one for incomming >> mails the mails within the domain might just be relayed like any other >> mail. This way the mails for the "own" domain also flowin like other >> mails from extern. There are other setups where your check wouldn't >> work.
If a SMTP daemon does not know about which domains it is responsible for, I would rate such a setup as broken by design. That would mean someone has given up lots of control about the setup. Doing all kinds of routing solely based on network addresses and such giving up on SMTP semantics, I do not understand why that may make sense. -- Christian
