Hi all,
Recently I've seen clients connecting to my sendmail server and then mails getting sent with FROM(for example
info@mydomain.com) of the local domain.
To stop this I added a FROM line in access map with
Code:
To:mydomain.com OK
FROM:mydomain.com ERROR:"550 Blablabla"
This seems to work fine. The users of the domain are using their ISP SMTP server for outgoing mail so the TO access line is matching.
There is only one corner case: forwarding/sending mails within the same domain(TO and FROM in mydomain.com): this returns a message undeliverable with the configured message.
Can I just disable processing outgoing mail for mydomain on that server and remove the FROM access rule? I figured the mail clients from the users are using the ISP smtp anyway. If I want to disable: any pointers?
Am I missing something here?
I know people can still go to an open relay and act like mail is coming from my domain(MAIL FROM/ENVELOPE). However the trail would not have my server in it.
I'm afraid that mails might seem legit (by for example antispam, ...) if they're actually passing through mydomain. Does this really make a difference?
