Better to fight for something than live for nothing. (George S. Patton)
FORTRAN—the "infantile disorder"—, by now nearly 20 years old, is hopelessly inadequate for whatever computer application you have in mind today: it is now too clumsy, too risky, and too expensive to use. (Edsger W. Dijkstra)
The Barracuda Spam Appliance really does an excellent job filtering spam. When one of my Kerio customers recently implemented that, he was very pleased with the results. There was one small wrinkle, though: email that Barracuda marks as Spam was not being filtered to the users Junk Email folders.
That's simple enough: Kerio marks its spam with "**SPAM**" by default and Barracuda uses "[SPAM]". We could either make them both agree or add a Custom Kerio rule that adds spam points when it sees the Barracuda tag. Making them both use the same tag is easy, so we tried that.
It didn't work. Puzzled, he tried the second method. That didn't work either and he could see in the rules section that the rule was not being triggered even though "[SPAM]" messages were coming through.
Well, duh: of course not. He doesn't check local users for spam and the inside address of the Barracuda is a local address.
We didn't want to turn that on, so instead we changed the Barracuda's address to be outside of the "local" IP range defined as able to relay.
But that caused other problems. Now the Kerio server didn't like the email arriving from an "untrusted" source. These limits had to be turned off:
However, as nothing but the Barracuda is coming from outside, and it can apply its own limits, turning these off is not opening up any security issues. With those off, the spam filtering could now take place and custom rules could work.
Don't forget that your Barracuda must be in your local DNS.