Block outbound smtp traffic

[mastang13]

I'm attempting to block all outbound smtp except from one computer on the inside with the following acl but it's not working. I have a few internal computers that are generating ramdom smtp emails to the internet(may be infected with virus) and would like to stop at pix.

access-list 101 permit tcp host 10.1.0.12 eq smtp any
access-list 101 deny tcp any eq smtp any
access-list 101 permit ip any any
access-group 101 in interface inside

 

[rudeboy]

Remember that the source machine is leaving on a random port but requesting the destination machine to answer on port 25(smtp). Below is how it should look.


access-list 101 permit tcp host 10.1.0.12 any eq smtp
access-list 101 deny tcp any any eq smtp
access-list 101 permit ip any any
access-group 101 in interface inside

 

[rudeboy]

I misread your post originally. I thought your machines were connecting to external mail servers on port 25. Your original access-list should work. Are you sure the source port is 25?