Mail for a domain just from known server(s)

[Robert Schuster]

If I know mail for domain xyz.tld can just be sent from server 111.111.111.111 or 222.222.222.222 how can I reject any mails for whatever@xyz.tld from any other server?
Of course the best solution would be a filter rule built at the PMG Interface, but a postfix hack is also welcome

regards

 

[Alwin]

If I know mail for domain xyz.tld can just be sent from server 111.111.111.111 or 222.222.222.222 how can I reject any mails for whatever@xyz.tld from any other server?

Add an 'WHO object' with the IP (-Range) to the whitelist for the domain (page 53).
https://www.proxmox.com/images/download/pmg/docs/pmg-admin-guide.pdf

 

[Robert Schuster]

Hi Alwin,

thanks for for the hint but this doesn't solve the challenge at all and yes - I've read the documentation.
Unfortunately there was a little typo in my question which makes the whole post more or less nonsense...
I wrote mail for domain xyz.tld where I've meant mail from domain xyz.tld.

So the right question is:
If I know mail from sender-domain xyz.tld can just be sent from server 111.111.111.111 or 222.222.222.222 how can I reject any mails from whatever@xyz.tld sent thru any other server

Sorry for the confusion
regards
Robert

 

[Alwin]

This calls for SPF and 'reject unknown sender' of postfix. This can be reached through Proxy -> Options. Then all mail sender that do not comply will be rejected. Else you will need to set the two rules, first allow then deny, making it more complicated later on, when there will be more server or domains. I suggest the first variant.