Problem: I had a user that wasn’t getting any internal / external emails.
There was nothing in the logs and nothing to indicate why the Local Delivery queue was stalled for all emails that had them as a recipient.

Troubleshooting: I Opened the Exchange System Manager and navigated to Administrative Groups ==> first administrative group ==> Servers ==> MYSBS2003 (this is the name of your server) and put the logging to maximum and then tried to send an email to the user. This is what was put into the Event Viewer Application Log:

Event Type: Warning
Event Source: MSExchangeTransport
Event Category: Exchange Store Driver
Event ID: 327
Date: 21/05/2009
Time: 3:24:59 PM
User: N/A
Computer: MYSBS2003
Description:
The following call : EcLocallyDeliverMsg to the store failed. Error code : -1605 (Message-ID <[email protected]>). MDB : c1506cc2-bb3b-49e2-8fa7-083342eb1d16. FID : 6-45CF70. MID : 6-463589. File : .

For more information, click http://www.microsoft.com/contentredirect.asp.

The fix:

1. log on as the user
2. open outlook and right click on the top level of the users exchange mailbox
3. Click on the permissions tab and add the user as an owner

Summation:
Although I can’t be 100% sure this fixed it. The email delivery started working immediately after this change was done.