My Apple Mail program (OS10.7.4) includes several rules for setting the background of messages from specific senders to a certain color in the viewer window. These rules have worked flawlessly up to Snow Leopard. With Lion, they work only intermittently: some of the messages in the inbox are colored, others from the same sender are not. Same problem and three different machines. The mail account is IMAP. If colored messages are moved to a different mailbox, the coloring may or may not be retained. Apple advisors were unable to solve this problem. At the end, they blamed it on Spamsieve, yet the problem persists even if Spamsieve is turned off. Then the Apple folks claimed that Spamsieve alters some of the fundamental coding of Mail, and these changes are not affected by turning Spamsieve off. They advised a complete reinstallation of Mail which would mean archiving all mail boxes. Not an attractive solution. I would be grateful for any comments from Spamsieve experts on the rules problem with Apple Mail.
I don’t think SpamSieve does anything that would cause this, but you can tell for sure by unchecking the SpamSieve rule in Mail’s preferences and removing SpamSieve’s plug-in:
/Users/<username>/Library/Mail/Bundles/SpamSieve.mailbundle
That will fully remove any effects from SpamSieve. There’s no need to reinstall Mail or archive your mailboxes.