Once the red cross is on the mailbox you have two options.
1. If you have deleted an
2. If you want to get rid of the mailbox totally, right click on the mailbox and
If you right click on an account without the red cross, the reconnect and purge options are disabled.
It plays no part in
It runs as part of online maintenance each night.
http://www.microsoft.com/technet/prodtechnol/exchange/2003/insider/exstoremaintain.mspx