our organization gets between 60000 to 80000 incoming emails a DAY. Of this, maybe 300 are legit. Most of these are directory harvesting attacks, so they just hit our gateway server and are discarded.
We currently use GFI products to manage SPAM. I like the ease of use, and the ability to tweak the spam rules (we are a reproductive research facility, so certain terms like 'meds' and ejac*late are perfectly acceptable business use and I need to be able to allow them) The licensing costs are a hit, but not outrageous considering the value added. I also like being able to restrict people from sending / receiving 10 full size digital images of baby's first tooth at one time. a curse to the inventor of the affordable digital camera.
I am concerned about the bandwidth hit on our perimeter server, so am looking at both trendmicro's and message lab's hosted solutions.
can someone who has experience with both advise on pros and cons, specifically with regard to cost, ability to customize, and ability filter out directory harvest attacks.
thanks in advance