I installed Postbox 3.0.6 and then added SpamSieve per instructions on c-command page. I should mention SpamSieve runs flawlessly and lightning fast with Apple Mail.
With Postbox, I have it configured to move spam to Junk On My Mac. It can take 30-60 seconds to process one incoming message and if I have a number of them, it pretty much hangs Postbox. By the way, with SpamSieve disabled, Postbox functions fine.
Any hints on how to make the Postbox / SpamSieve integration fast?
This is due to a bug in Mac OS X 10.8.2. Please contact me via e-mail, and I’ll send you a pre-release version of SpamSieve that tries to work around the problem.