Can I safely block port 25 on my server?
October 26, 2007 12:55 AM Subscribe
Can I block port 25 or not?
posted by ajbattrick to Computers & Internet (5 answers total) 3 users marked this as a favorite
I'm working on the firewall of a public facing webserver at the moment, and want to block TCP port 25 (SMTP) to incoming traffic as I'm seeing many connections that I just don't want to accept. The server does not handle any incoming email so this would usually be a no-brainer, just block and forget about it.
However, the server is sending around 25000 emails to a distribution list, two or three times a week. I am sure that AOL, or some other big email providers will block emails coming from servers that do not have port 25 open.
I don't want to just block it to test this and have a load of failed emails to deal with.
Do you know if I need to leave port 25 open or not?