This morning, my iPhone Mail.app started to crash continuously. After I open the application. It keeps running for a while, then crashing to the home page. I am not sure what triggers the crash though I will keep this post updated if things get fixed. I use a non-jailbroken up-to-date iPhone with Gmail and Yahoo accounts set up.

Update 1: I have found out that my Yahoo! account checking my SBS e-mail is crashing the Mail.app. Disabling it temporarily helped.

Update 2: I believe I am back to normal. The problem seems to be the result of 1200 messages in my Yahoo! inbox. I have archived them and things seem to be OK now. Though I had the much trouble archiving them.