Mail crashes and quits immediately upon launch every time

Question

Every time I launch Mail, it crashes, quits, and throws the following error to the console:
*com.apple.launchd[68] ([0x0-0x78078].com.apple.mail[854]) Exited abnormally: Segmentation fault*
When I remove Preferences/com.apple.mail.plist and Mail from my ~/Library/, Mail will launch and allow me to enter settings, but crashes and quits after setup, throwing this error to the console instead:
*com.apple.launchd[68] ([0x0-0x73073].com.apple.mail[830]) Exited abnormally: Bus error*
I created another user account on this computer, and I was able to et up and run Mail smoothly under the alternative login. I also set up Thunderbird with the same settings in my primary user account, without any problems-- but Thunderbird's implementation is somewhat lackluster.
I'm running Mail 3.5 (930.3) on a new Aluminum MacBook with OS 10.5.6. Mail has always run flawlessly on my other machine, using identical settings with the same IMAP account, but that machine runs OS 10.4.11.
This problem has persisted since 19 December, and I can furnish the crash report if needed. Prior to this, I experienced intermittent Mail freezes and other problems.

Answer 1

Every time I launch Mail, it crashes, quits, and throws the following error to the console:
*com.apple.launchd[68] ([0x0-0x78078].com.apple.mail[854]) Exited abnormally: Segmentation fault*
When I remove Preferences/com.apple.mail.plist and Mail from my ~/Library/, Mail will launch and allow me to enter settings, but crashes and quits after setup, throwing this error to the console instead:
*com.apple.launchd[68] ([0x0-0x73073].com.apple.mail[830]) Exited abnormally: Bus error*
I created another user account on this computer, and I was able to et up and run Mail smoothly under the alternative login. I also set up Thunderbird with the same settings in my primary user account, without any problems-- but Thunderbird's implementation is somewhat lackluster.
I'm running Mail 3.5 (930.3) on a new Aluminum MacBook with OS 10.5.6. Mail has always run flawlessly on my other machine, using identical settings with the same IMAP account, but that machine runs OS 10.4.11.
This problem has persisted since 19 December, and I can furnish the crash report if needed. Prior to this, I experienced intermittent Mail freezes and other problems.