Hi .. assuming your smtp server uses the standard 25 protocol .. then your access list is OK as long as it is being applied to the interface where the server resides. !!! NOTE: make sure the smtp server has a dns server configured for dns resolution as well .. !!! i.e perform a nslookup and test dns resolution ..
make sure to add a permit ip any any at the end otherwise your would only allow smtp outbound blocking everything else
Yes, my mail server uses port 25. It resides on the 'inside' interface, and I am applying the rule to outbound traffic only. I also have an allow ip any any at the end of the rule to allow all remaining traffic after the unwanted SMTP traffic has been blocked.
What do you mean by make sure I have a DNS server configured for it? If you mean MX records I am covered.
We have configured the outside and inside Interface with official ipv6 adresses, set a default route on outside Interface to our router, we also have definied a rule , which also gets hits, to permit tcp from inside Interface to any6.
In Syslog I also se...