Mail will not open message viewer or drafts

Question

Hello.  I work on a 27" IMac 2.66 GHz 8 GB 1067 MHz DDR3, running Mavericks 10.9.5.  Since installing the latest update mac mail has been running VERY slowly, even lagging substantially as I type.  Then in the last couple of days it has seemingly launched but no windows, no message viewer are visible.  I can quit it or force quit or restart the computer but it still will not open any windows.  I tried shutting off iCloud mail sharing yesterday and lo and behold it worked again.  But today although iCloud mail remains shut off it will not open.  I have opened the console and here are the recent messages:
(it seems to suggest I am out of cpu space? of a 1TB SATA disk I have 387.21 GB free of 999.35
Your assistance in fixing this will be greatly appreciated.  Thank you.
10/10/14 1:05:51.237 PM WindowServer[190]: disable_update_timeout: UI updates were forcibly disabled by application "Mail" for over 1.00 seconds. Server has re-enabled them.
10/10/14 1:05:51.949 PM com.apple.SecurityServer[14]: Session 100023 created
10/10/14 1:05:52.517 PM Mail[756]: The layout constraints still need update after calling -[MUIAddressField updateConstraints].  MUIAddressField or one of its superclasses may have overridden -updateConstraints without calling super. Or, something may have dirtied layout constraints in the middle of updating them.  Both are programming errors.
10/10/14 1:05:52.918 PM WindowServer[190]: common_reenable_update: UI updates were finally reenabled by application "Mail" after 2.68 seconds (server forcibly re-enabled them after 1.00 seconds)
10/10/14 1:08:10.085 PM com.apple.backupd[725]: Found 2371 files (1.23 GB) needing backup
10/10/14 1:08:11.000 PM com.apple.backupd[725]: 2.39 GB required (including padding), 12.71 GB available
10/10/14 1:08:41.000 PM kernel[0]: process Mail[756] thread 27827 caught burning CPU! It used more than 50% CPU (Actual recent usage: 51%) over 180 seconds. thread lifetime cpu usage 90.223218 seconds, (88.660322 user, 1.562896 system) ledger info: balance: 90001796449 credit: 90001796449 debit: 0 limit: 90000000000 (50%) period: 180000000000 time since last refill (ns): 173696420474
10/10/14 1:08:41.865 PM ReportCrash[779]: Invoking spindump for pid=756 thread=27827 percent_cpu=51 duration=177 because of excessive cpu utilization
10/10/14 1:08:46.717 PM spindump[780]: Saved cpu_resource.spin report for Mail version 7.3 (1878.6) to /Library/Logs/DiagnosticReports/Mail_2014-10-10-130846_Rachael-Millers-iMac.cpu _resource.spin
10/10/14 1:08:53.843 PM com.apple.SecurityServer[14]: Session 100011 created
10/10/14 1:08:53.843 PM com.apple.SecurityServer[14]: Session 100024 created
10/10/14 1:10:04.098 PM com.apple.backupd-helper[59]: Not starting scheduled Time Machine backup: Backup already running
10/10/14 1:12:05.990 PM mdworker[785]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 1. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
10/10/14 1:12:05.990 PM mdworker[793]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 1. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
10/10/14 1:12:05.990 PM mdworker[792]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 1. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
10/10/14 1:12:09.546 PM mdworker[786]: CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 1. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.
10/10/14 1:12:15.637 PM mdworker32[795]: CGSConnectionByID: 0 is not a valid connection ID.
10/10/14 1:12:15.637 PM mdworker32[795]: CGSGetSpaceManagementMode: No connection with id 0x       0
10/10/14 1:12:50.991 PM com.apple.backupd[725]: Copied 2694 items (1.14 GB) from volume Macintosh HD. Linked 11878.
10/10/14 1:13:01.539 PM com.apple.backupd[725]: Will copy (9.2 MB) from Macintosh HD
10/10/14 1:13:01.540 PM com.apple.backupd[725]: Found 106 files (9.2 MB) needing backup
10/10/14 1:13:01.540 PM com.apple.backupd[725]: 928.5 MB required (including padding), 11.46 GB available

Answer 1

Back up all data before proceeding.
1. Triple-click anywhere in the line below on this page to select it:  
~/Library/Mail/Bundles
Right-click or control-click the highlighted line and select
          Services ▹ Open
from the contextual menu.* A folder may open, or you may get an error message that the item can't be found. Either result is normal. If the folder does open and has contents, move the contents to the Desktop. Relaunch Mail and test. If there's no change, put the contents of the folder back and quit Mail again.
2. Repeat with this line:
/Library/Mail/Bundles
This time you may be prompted for your administrator login password when you remove the items. Make sure they're removed from the folder and not just copied to the Desktop. If necessary, copy them first and then move the originals to the Trash.
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination  command-C. In the Finder, select
          Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You won't see what you pasted because a line break is included. Press return.