Deleting an account/mailbox is a bad idea. You're not likely to find an admin willing to do that.
Deleting the device's sync from the account is another thing - that's no big deal. If that's what you meant, you should clarify.
Also, making a PST backup of a mailbox and recreating the mailbox is messy - not recommended, especially for something so trivial as a phone sync. Just take the Thunderbolt back and tell Verizon that the product is incomplete. Then pick up ANY other Android or even a BB (if your company supports BES), since they function out-of-box.
It's apparent that the issue is with the sync coding that's baked into the Thunderbolt, not the domain account or exchange mailbox.
When OS 2.2 was released, the sync baked into the original Droid broke and it took months for that to get resolved. (I think Motorola was even buying users the full version of Touchdown to compensate). Right now the QA teams between Google and Verizon (and now HTC) don't rank very high to me.
From what I understand, the Thunderbolt is only syncing newly created/modified calendar events, and some (all?) events accepted in Outlook don't push to the phone. Why is that? And yes, this is where deleting and re-creating a mailbox *might* "fix" this issue (I haven't and won't bother testing this), but only because all the calendar events may be re-created when you copy the backup calendar back. But that's not a solution. That's a sloppy patch job that puts the responsibility on company admins... The easier, faster, and better solution becomes this: "We don't currently support the HTC Thunderbolt here at [company name] as it is incapable of syncing fully with Exchange"
Here's what I think HTC/Verizon/Google (all those that are responsible for this epic QA fail) should do:
1) acknowledge the users (us) and tell us their aware of the issue with their product.
2) put their heads together and fix it instead of passing the buck around
