I agree. The Mail client is constantly beach ballin and freezes at times. The issue is resolved by deleting the account and recreating it again. Surely not as intended. Especially for an app that virtually everyone on a Mac uses on a daily basis. I keep sending my crash reports but Mail client software updates seems to never come...

Also, another really annoying bug is when screensaver goes on and locks the screen. Sometimes, if I try and wake it up to fast it will freeze with a black screen for 60-120 seconds before I can unlock it again.