I am migrating from Ex2003 to Ex2010.
I have the old "Could not delete source mailbox" problem. With the majority of Mailboxes running the cleanup agent a few times sorts it.
However there are 2 that are well and truly stuck.
Things I have tried, in no particular order:
Setting Maintenance Limit to 0 days
Deleting mailbox results in it deleting it from Ex2010 also. Outlook cannot connect to either databases.
I tried changing the homeMDB and MTA values manually, to the right values. The Mailboxes now both show with a red X (progress...) in Ex2003 but still unable to purge as it thinks its still connected.
Event log shows maintenance for some reason keeping those mailboxes also.