This seems to be a very common complaint from the field - Deleted mailboxes will appear in disconnected mailbox list, but these changes it will not reflect immediately. You have to wait for online maintenance to run and complete before the mailboxes are correctly listed
If you accidentally delete mailbox and if you wanted to reconnect it back then I suspect you will not be able to find it Disconnected Mailbox. Dont panic, you dont have to wait for OLM, you can run the cmdlet Clean-MailboxDatabase to get the deleted mailbox to show up in the right place. Also, if you want to disconnect the mailbox to re-add it to an other user or the same user do the following:
Clean-MailboxDatabase \servername\SGName\StoreCleans an individual database
Get-Mailboxdatabase | Clean-MailboxDatabaseCleans all the databases in the Organization
Hope this helps :)
The clean command on exchange 2010 for a single database is "Clean-MailboxDatabase [nameofdatbase]" such as
Can this command be run in production mode, or offline mode.