For some time now I receive a lot of spam emails. The emails are all different but if I lookup the domain of the email address it always resolves to the same IP address.
- firstname.lastname@example.org -> resolves to 184.108.40.206
- email@example.com -> resolves to 220.127.116.11
In postfix I can reject each email address but in this case it is not helpful because the email address changes all the time.
The next problem I have is that each email is send through a different mail server. So I cannot block by sender address.
What I would like to do is block an email by the ip address. Not that of the sender but of the ip address of the domain used as part of the email.
Any suggestions on how this is done in postfix?