Better Email Security with Procmail - page 3
All in all, this software is a useful addition to my armoury. It is by no means a replacement for traditional virus-killers; it shouldn't be taken as such. It is vital that you take proper precautions all the way down the line, and try to stay vigilant. For the price, though (free), it's a steal. It doesn't give you carte blanche to throw out your client virus scanners; in fact, take the opportunity to set up a routine to keep them up to date, if you haven't already. The scanner targets (in a lot of cases) different vulnerabilities, and should be a compliment to decent virus defences. Some vendors have server-side email scanners, but they are expensive, and a lot are NT-based. Obviously, this would have a fairly serious effect on overall system security and reliability (not to mention cost). Also, some vendors offer client-side email scanners. Beware of the underlying AV engine, however, since some have fundamental flaws which preclude their use as a general file scanner, let alone an email scanner. In the case of an either/or choice (budgets are finite, after all), choose a good general-purpose AV product, and keep it up to date. My personal favourite enduser scanner is Datafellows F-Secure on workstations, on account of first-class network admin features, but other people's mileage may vary.
I would suggest that you trial this software on a non-production or small volume basis before rolling it out. This is just common sense. The open-source nature of the system allows you to take a look at the workings, and make a reasonably educated guess as to what it does.
If, like me, you have to deal with feckless email users who never quite manage to practise Safe Hex, you'll find this a godsend.