Mail crashes when retrieving from one particular mailbox/account

Question

I'm able to get email from several other accounts, but the main account/mailbox is causing a crash each and every time it tries to retrieve the mail. I've done some due diligence but don't see any answers that fit, other than a need to remove/replace a plist (http://crispierry.typepad.com/applepie/2006/09/mailappkernpr.html). Before I did this, thought I'd post here. Is there a simple way of deleting the problem email (if in fact it is an individual email that's gumming up the works)?
Thanks in advance for any advice.
Including the top of last three crash reports:
Process: Mail [1617]
Path: /Applications/Mail.app/Contents/MacOS/Mail
Identifier: com.apple.mail
Version: 4.2 (1077)
Build Info: Mail-10770000~4
Code Type: X86-64 (Native)
Parent Process: launchd [123]
Date/Time: 2010-02-08 14:38:26.636 -0500
OS Version: Mac OS X 10.6.2 (10C540)
Report Version: 6
Interval Since Last Report: 19515 sec
Crashes Since Last Report: 36
Per-App Interval Since Last Report: 9307 sec
Per-App Crashes Since Last Report: 36
Anonymous UUID: FEF1B1E6-4526-4FA8-B82F-8259280B5943
Exception Type: EXCBADACCESS (SIGBUS)
Exception Codes: KERNPROTECTIONFAILURE at 0x0000000100690fa0
Crashed Thread: 2 Dispatch queue: com.apple.root.default-priority
Application Specific Information:
-[POPAccount fetchSynchronouslyIsAuto:]
-[MessageRouter routeQueuedMessages]
-[POPAccount fetchSynchronouslyIsAuto:]
Thread 0: Dispatch queue: com.apple.main-thread
0 libSystem.B.dylib 0x00007fff88852e3a machmsgtrap + 10
1 libSystem.B.dylib 0x00007fff888534ad mach_msg + 59
Process: Mail [1651]
Path: /Applications/Mail.app/Contents/MacOS/Mail
Identifier: com.apple.mail
Version: 4.2 (1077)
Build Info: Mail-10770000~4
Code Type: X86-64 (Native)
Parent Process: launchd [123]
Date/Time: 2010-02-08 14:48:45.031 -0500
OS Version: Mac OS X 10.6.2 (10C540)
Report Version: 6
Interval Since Last Report: 20129 sec
Crashes Since Last Report: 37
Per-App Interval Since Last Report: 9346 sec
Per-App Crashes Since Last Report: 37
Anonymous UUID: FEF1B1E6-4526-4FA8-B82F-8259280B5943
Exception Type: EXCBADACCESS (SIGBUS)
Exception Codes: KERNPROTECTIONFAILURE at 0x0000000100690fa0
Crashed Thread: 13 Dispatch queue: com.apple.root.default-priority
Application Specific Information:
-[MessageRouter routeQueuedMessages]
-[POPAccount fetchSynchronouslyIsAuto:]
Thread 0: Dispatch queue: com.apple.main-thread
0 libSystem.B.dylib 0x00007fff88852e3a machmsgtrap + 10
1 libSystem.B.dylib 0x00007fff888534ad mach_msg + 59
Process: Mail [1680]
Path: /Applications/Mail.app/Contents/MacOS/Mail
Identifier: com.apple.mail
Version: 4.2 (1077)
Build Info: Mail-10770000~4
Code Type: X86-64 (Native)
Parent Process: launchd [123]
Date/Time: 2010-02-08 14:54:39.649 -0500
OS Version: Mac OS X 10.6.2 (10C540)
Report Version: 6
Interval Since Last Report: 20483 sec
Crashes Since Last Report: 38
Per-App Interval Since Last Report: 9378 sec
Per-App Crashes Since Last Report: 38
Anonymous UUID: FEF1B1E6-4526-4FA8-B82F-8259280B5943
Exception Type: EXCBADACCESS (SIGBUS)
Exception Codes: KERNPROTECTIONFAILURE at 0x0000000110500fa0
Crashed Thread: 11 Dispatch queue: com.apple.root.default-priority
Application Specific Information:
-[POPAccount fetchSynchronouslyIsAuto:]
-[MessageRouter routeQueuedMessages]
Thread 0: Dispatch queue: com.apple.main-thread
0 libSystem.B.dylib 0x00007fff88852e3a machmsgtrap + 10
1 libSystem.B.dylib 0x00007fff888534ad mach_msg + 59

Answer 1

Create a New User Account, and as that New User try to set up this one account -- if POP set to leave messages on the server after download. If not familiar with setting up a New User Account, see:
http://docs.info.apple.com/article.html?path=Mac/10.5/en/8235.html
This will be a useful test, and it not meant to suggest a permanent switch to the New User Account, but rather a test of the Mail application outside of your normal User Account.
Ernie