What are the dangers of opening port 25 to allow smtp traffic through? I have a windows server 2003 box which has port 25 blocked (Not by ISP), I know ISP's for usually block this port from use but as I need it for some php scripts I'm running that notify users by email, Is there any dangers or precautionary actions I should take?
Any advice would be appreciated,
Thanks Luke.
If you are thinking of unblocking port 25 on outbound traffic then no, not really. If you are wanting unblock port 25 on incomming traffic to receive email from external scripts into your internal mail server then you need to ensure you have the mail server configured to prevent relaying etc.