IMAPCheck is a bundle for Mail.app that fixes an issue with iMap support. Namely, when using server side rules to re-route email into folders, Mail.app wouldn't see the new mail until you actually clicked on the subfolder. This bundle changes the way Mail checks for new email on IMAP accounts by forcing it to sync all the folders every time.
As of mail 3.0, if your IMAP server supports IDLE, you won't see a significant traffic InCrease. If your mail server does NOT support IDLE, this will increase the traffic between you and the mail server a bit, however, it is only exchanging message IDs so until you go to download the actual message, it won't be significantly more data.
A known limitation of IMAPCheck is that it still does not enable rules support on IMAP accounts. This bundle WILL allow Mail.app to see the new email, but it still doesn't Process rules in those folders (this was true of Mail 2, I haven't tested Mail 3). I looked briefly into enabling rules on these folders, but it seems to be something built directly into POP Account support. I do Think it would be possible to write a bundle to fix rules processing, but it would require more development and testing time than I have to dedicate to it.
Compatibility: Universal binary. Developed and tested against version 3.0 of Mail.app on 10.5.0 with all the latest patches as of 1 Nov 2007. It has been tested on both PPC and Intel. Tested the plugin against Mail 2 on 10.4.10 as well and it worked, however the Installer is specific to 10.5 and Mail 3.
