mail started crashing after update

Mail on my mac suddenly started crashing. I get a long msg. say it unexpectedly closed. It has logged 11 crashes and still won't stay running. I'm able to use the mail @icloud.com but not on my mac. What happened and what do I do to repair it? I'm running OS X ver. 10.7.2 Lion. It was working fine yesterday morning then started to crash in the afternoon. Still unable to use, continues to crash.