Mail.app crashes on launch consistently

Question

Up until yesterday, my upgrade to Mountain Lion had been completely smooth.  Today when I launch mail, it crashes consistently on thread 0.  So I did the Windows rule of rebooting first off.  no joy
I tried restoring the app via Time Machine and it crashes as well so the problem cause remains unknown.
I have tried this with iCloud sync both on and off and also tried resetting sync services since this used to be a fix in the old days with Lion and Snow Leopard although I think it no longer applies with iCloud. 
I've also tried removing the envelope index files and even all the plist files but the app does not launch long enough or far enough to get there.
I've also done a Repair disk permissions and while it found tons of faults, mostly in the printers area, this did not resolve the issue.
At this point, Mail is unusable which is a major pain in the ***.  if anyone has solutions, I'd appreciate hearing.
Ross

Answer 1

I'm having the same problem as JadedEye.   Mail.app worked just fine yesterday, but now I can't get it to launch.
I've tried your suggestion, hpr3, to use Safe Mode.   No luck.
Other things I've tried:
1. Using recovery partition, repaired disk - no problems
2. Using recovery partition, repaired permissions - nothing that looked as if it were related.
3. Tried restoring Mail.app through Time Machine
4. Tried restoring entire ~/Library/Mail folder from yesterday
5. Tried deleting Mail Envelope files
6. Tried removing entire ~/Library/Mail and ~/Library/Mail Downloads folders
7. Tried deleting preferences files -- only one I found was com.apple.mail.plist.lockfile
NONE of these things has made any difference.  I would re-install Mail.app, if I could find an installer package anywhere.
I've copied the header and footer of the crash report below:
Process:         Mail [632]
Path:            /Applications/Mail.app/Contents/MacOS/Mail
Identifier:      com.apple.mail
Version:         6.0 (1485)
Build Info:      Mail-1485000000000000~3
Code Type:       X86-64 (Native)
Parent Process:  launchd [245]
User ID:         501
Date/Time:       2012-08-01 19:44:01.482 -0400
OS Version:      Mac OS X 10.8 (12A269)
Report Version:  10
Interval Since Last Report:          331251 sec
Crashes Since Last Report:           17
Per-App Interval Since Last Report:  276196 sec
Per-App Crashes Since Last Report:   15
Anonymous UUID:                      FCE49931-23F4-4817-A753-154DA076FBDB
Crashed Thread:  0  Dispatch queue: com.apple.main-thread
Exception Type:  EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: KERN_INVALID_ADDRESS at 0x0000000000000000
VM Regions Near 0:
-->
    __TEXT                 00000001094da000-0000000109877000 [ 3700K] r-x/rwx SM=COW  /Applications/Mail.app/Contents/MacOS/Mail
TOTAL                             394.2M
Model: iMac7,1, BootROM IM71.007A.B03, 2 processors, Intel Core 2 Duo, 2.4 GHz, 4 GB, SMC 1.21f4
Graphics: ATI Radeon HD 2600 Pro, ATI,RadeonHD2600, PCIe, 256 MB
Memory Module: BANK 0/DIMM0, 2 GB, DDR2 SDRAM, 667 MHz, 0x2C00000000000000, 0x3136485446323536363448592D3636374731
Memory Module: BANK 1/DIMM1, 2 GB, DDR2 SDRAM, 667 MHz, 0x2C00000000000000, 0x3136485446323536363448592D3636374731
AirPort: spairport_wireless_card_type_airport_extreme (0x14E4, 0x88), Broadcom BCM43xx 1.0 (5.10.131.36.16)
Bluetooth: Version 4.0.9f8 10405, 2 service, 18 devices, 1 incoming serial ports
Network Service: Ethernet, Ethernet, en0
Serial ATA Device: WDC WD30EZRX-00MMMB0, 3 TB
Parallel ATA Device: MATSHITADVD-R   UJ-85J
USB Device: USB2.0 Hub, 0x05e3  (Genesys Logic, Inc.), 0x0606, 0xfa400000 / 3
USB Device: USB2.0 Hub, 0x05e3  (Genesys Logic, Inc.), 0x0606, 0xfa410000 / 4
USB Device: MP560 series, 0x04a9  (Canon Inc.), 0x173e, 0xfa413000 / 8
USB Device: C-Media USB Headphone Set, 0x0d8c  (C-MEDIA ELECTRONICS INC.), 0x000c, 0xfa412000 / 7
USB Device: USB to ATA/ATAPI Bridge, 0x152d  (JMicron Technology Corp.), 0x2352, 0xfa411000 / 6
USB Device: Keyboard Hub, apple_vendor_id, 0x1006, 0xfa200000 / 2
USB Device: Apple Keyboard, apple_vendor_id, 0x0220, 0xfa220000 / 5
USB Device: Built-in iSight, apple_vendor_id, 0x8502, 0xfd400000 / 2
USB Device: Bluetooth USB Host Controller, apple_vendor_id, 0x8206, 0x1a100000 / 2
USB Device: IR Receiver, apple_vendor_id, 0x8242, 0x5d100000 / 2