Avast cannot scan outgoing mail

[system]

I get an error that avast cannot scan outgoing mail. Says port 25 is being used by another program. I am using a HP, laptop, pentium 2.66ghz, 512 mb ram. Window XP Pro. I have an outlook express 6.0 program as well as Outlook 2003 on my computer. I have tried changing the port as suggested and I still get the error when the computer starts up. Both of my email programs, still work properly, but get error on startup and not scanning my outgoing mail.
Any suggestions.

[Lisandro]

@miket601

I get an error that avast cannot scan outgoing mail. Says port 25 is being used by another program. I am using a HP, laptop, pentium 2.66ghz, 512 mb ram. Window XP Pro. I have an outlook express 6.0 program as well as Outlook 2003 on my computer. I have tried changing the port as suggested and I still get the error when the computer starts up. Both of my email programs, still work properly, but get error on startup and not scanning my outgoing mail.
Any suggestions.

Try TCPView… (http://www.sysinternals.com/files/tcpview.zip)
You will discover a lot about which program is opening each port…