Why is mail so slow?

Mac OS X Lion (10.7): Why is Mail.app is so slow?

• When I switched from Leopad to Lion, everything is much faster except mail.app, why? I removed mail < 1.months and still a dog slow. Especially with html emails. Im using threaded version (but also in old mail).

• Answer:

  While most people don't seem to experience this, it does happen and there's several discussions in the Apple forums about the subject with various solutions. I have not personally experienced it. However, all of the issues seem to be associated with a botched migration from an old version of Mail to a new one. The various solutions that have been reported to work: Use disk utility to repair permissions. Repair the keychain. (Open Keychain Access. Select Keychain Access > Keychain First Aid ... check the 'repair' box and click OK) Trash your mail preferences. (delete ~/Library/Preferences/com.apple.mail.plist) Remove and restore your Contacts: sync the Contacts to iCloud. Disable iCloud sync. Delete your Contacts (move ~/Library/Addressbook elsewhere). Turn on iCloud contacts sync to recreate you local Contacts. ... those various actions are attributed variously to fixing the problem. However,  I've never known anyone that has experienced the problem on their Macs, so I have never had the opportunity to investigate it.