Just curious if anyone is doing any greylisting on their systems? If so, have you noticed a dramatic decline in the amount of spam that gets through to SA? Sounds like an interseting concept that I'm thinking of trying out, but thought I'd see if anyone had any comments about it first.
There's been some implementations using MIMEDefang that are reportedly quite effective. Check the MD list archives for the code to include in your MD filter. Or buy Can-It, the commercial version of MD, which includes greylisting and a bunch of other stuff.
