First off, if you are sending mails that does not mean you have to receive them too. Just limit (effectively forbidding) mail receipt.

Second, there are no known viruses for AIX at all, so what would you need a virus scanner for? Virus scanner are for Windows machines because the OS is so poorly designed that there is an avalanche of malware possible and an equal avalanche of ways to apply same open. This is not so with AIX.

Third: viruses and other malware do not spread by magic. The most common way to infect machines is to have mail programs automatically execute every executable attachment they receive. This is simply not the case with AIX's mail client. So even if you would receive a mail containing malware and even if your setup is not to drop incoming mail without notice and even if it would do damage if run: you, as the receiver of the mail, would still have to consciously run it to execute it all. Until this it is just another string of data and harmless.

I hope this helps.

bakunin