Issue: Outlook’s To-Do Bar is no longer working after a mailbox is forced migrated (-badlimit specified) to Exchange 2010. Further, the To-Do list may display in cached mode, but will not show up with cached mode disabled.
Solution:
1) Migrate mailbox BACK to Exchange 2003
2) Use MFCMAPI and hard delete (permanent/unrecoverable) “To Do Search” folder in the mailbox’s Root Container
3) Run “Outlook /ResetTodoBar” (see using Outlooks clean /switches for complete command)
4) Verify TODO bar works now, close Outlook
5) Migrate mailbox to Exchange 2010 with NO badlimit argument
Once migration has completed, open Outlook and verify the TODO-bar is working properly
Workaround: Affected users enable cached mode in Outlook.
To clean corrupted items before moving mailboxes thus avoiding post migration ToDo Bar issues:
1) Setup a new account with full access to the mailboxes reporting corruption
2) Run Outlook switches on those accounts, one at a time.
In about 80% of corrupted mailboxes, /cleanfinders will fix the problem, and the mailbox will move without reporting any further corruption. For the remaining 20%, /cleanreminders and/or /resettodobar should fix almost all of them. However, on a few remaining mailboxes, it may be necessary to log into them with MfcMAPI and delete the “Reminders” or “Tracked Mail Processing” folders (*not* using a hard deletion). The mailbox moves should then able to complete without reporting corruption, and those users should in turn not lose their To-Do bars. Users with individual messages or calendar items that are corrupted should not report To-Do bar problems when their corrupted mailbox items are skipped.
Additional insight into determining what may be causing a mailbox migration to fail:
Most often corrupted items are default mailbox folders, especially search folders. If the mailbox move fails at 10% The problem is with a default mailbox folder; if it fails at a higher percentage, the problem is with individual corrupted items.
Additional Resources:
https://social.technet.microsoft.com/Forums/en-US/89902f00-4b84-4f10-b909-121a81241c85/can-not-move-exchange-2003-mailboxes-to-exchange-2010?forum=exchangesvrdeploylegacy
TODO Bar issues when forcing mailbox moves that encountered corrupted items: https://social.technet.microsoft.com/Forums/en-US/exchangesvrmigration/thread/89902f00-4b84-4f10-b909-121a81241c85/
Possible To-Do Bar Error messages:
“Cannot display the folder.”
“The operation failed. An object could not be found.”