said by wirelessdog:There is a script I run on Mikrotik so if too many messages are sent out port 25 in a 24 hour period their IP is blacklisted from using port 25.
Beyond that, I don't block any ports to end users and that is how it should be IMHO. We are ISP's not firewall providers.
I am not sure about the microtik stuff.
By blocking outgoing port 25, if the subscriber's email provider wont give them a secure smtp service, then the subscriber must use our smtp server on port 25.
Each ip address within our network can relay out through it, but is limited to 15 outgoing messages per hour unless they login.
Thats basically how i manage it.