Just upgraded to Yosemite (10.10.1). Apple Mail is crashing soon after opening. I'm getting the following problem report. Any ideas as to what the problem may be? Is one of my mailboxes corrupted? Thanks. In the meantime, I downloaded and installed Thunderbird so I can get my work done. Process: Mail  Path: /Applications/Mail.app/Contents/MacOS/Mail Identifier: com.apple.mail Version: 8.1 (1993) Build Info: Mail-1993000000000000~1 Code Type: X86-64 (Native) Parent Process: ???  Responsible: Mail  User ID: 501 Date/Time: 2014-11-18 12:52:47.495 -0600 OS Version: Mac OS X 10.10.1 (14B25) Report Version: 11 Anonymous UUID: 22C93C86-182F-CE37-1D24-BAA3CE173BE4 Time Awake Since Boot: 580 seconds Crashed Thread: 13 -[MFIMAPAccount fetchSynchronouslyIsAuto:] Dispatch queue: NSOperationQueue 0x608000258960 :: NSOperation 0x610001445640 (QOS: LEGACY) Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Application Specific Information: *** Terminating app due to exception while holding database lock 'NSInternalInconsistencyException', reason: '<MFEWSStore: 0x6000001f6900 (mailbox=<MFMailbox:0x7fdc0a630720 (relative path=Inbox, attributes=0, displayName=NSCC Exchange uuid=8C4EE726-599A-48DE-8AB5-567DBC40C097)>)> is not a Library IMAP store' abort() called Note: I can't include the entire report as it exceeds the character limit.