How to change the server settings of Thunderbird to use Exchange 2013?

Change the server setting to cas2013.exchange.ust.hk after you received the migration notification. If you cannot read messages after migrated to Exchange 2013, just change the server setting to cas2013.exchange.ust.hk and message will be reloaded again.

Although the server imap.ust.hk can redirect your IMAP connection to Exchange 2010 or 2013, , cas2013.exchange.ust.hk gives the best performance and features with IMAP clients and it is our recommendation.

If your Thunderbird is using the old server "cas.exchange.ust.hk", you will not be able to read new messages after the migrated to Exchange 2013. You can change your Thunderbird to use the new server setting no matter your Exchange account is on the 2010 server or 2013 server except that your may encounter a warning message "error 12" during start up of your Thunderbird client. The error message will gone after migrated to Exchange 2013.

Steps to change the server setting

1. Invoke Thunderbird
2. Select Account Settings under the Tools menu
3. Click Server Setting on the left pane
4. Change the Server Name to cas2013.exchange.ust.hk
   
5. Click OK to save the changes and restart Thunderbird