Re: Wait, what?
blocking port 25 should be done by all consumer ISPs. If you want to use port 25 then that should be possible if you can prove you're not relaying spam.
If you run your own SMTP server for clients to connect you should be running it on a different port over SSL with auth.
The reason for blocking port 25 is to stop spam bots from sending emails.
If you don't know this stuff you shouldn't be running an SMTP server.