Mail is crashing everytime an email is selected with attachment, I have only one email with attahment in inbox and as soon as I open Mail it crashes. Any help?
Found this solution:
First thing to do is to open Mail while holding the shift key down. This prevents any messages loading at startup - and if any such message has corrupted content it will cause this kind of behavior. Launching Mail with the shift key down will allow you to look through messages and try and spot the problematic one(s).
If that doesn't help, then with Mail closed, open your users>your user name>library>caches>mail folder and delete any content there, then try and relaunch Mail. Damaged cache content can cause Mail instabilities.
There is also a suggestion that it may help to delete 'to do' items!