smtp forwarding and antivirus scanning

[Guest]

[cml800]

I'm a bit new to Endian so pardon my ignorance if this is an elementary question.  I've searched the forums but can't seem to get a definitive answer.

If I configure a firewall rule to forward smtp traffic to my mail server, and I do not use the smtp proxy service, does the traffic get scanned for viruses?  I recently configured EFW2.3 to forward smtp traffic to my mail server.  As a test, I disabled the scanning software on the server (which works well but keeps my server busy all the time) and within a few hours I had a virus.  I re-enabled the virus scanning software on the server and it picked up the virus immediately.  So either the smtp traffic was not being scanned or the EFW scanner isn't very good.

If I use smtp proxying, is there any need for firewall rules?