Ran into a strange issue recently when a client upgraded from Exchange 2010 to Exchange 2016. The client had already decommissioned Exchange 2010 so coexistence was not a factor. Their configuration was a single-server running Exchange 2016. All mailboxes were located on a single database.
Outlook clients would work fine internally. Externally Outlook would never connect. The status bar would simply report ‘Trying to connect’. Outlook on the Web and all ActiveSync clients were working fine. In addition, the Autodiscover test on the Microsoft Remote Connectivity website was passing.
In contrast, the Outlook Connectivity test from the same site was failing. The following error was reported.
Testing the MAPI Mail Store endpoint on the Exchange server. An error occurred while testing the Mail Store. Additional Details Elapsed Time: 919 ms. Test Steps Attempting to log on to the Mailbox. An error occurred while logging on to the Mailbox. Additional Details Mailbox logon returned ecLoginFailure -2147221231. Possible causes are: 1. The user doesn't have any access to a private mailbox or public folder messaging data. 2. There are no private mailboxes or public folders on the server. 3. The server is exiting or is about to exit. StatusCode: -2147221231
The possible causes identified by the error were equally vague. We confirmed these user credentials were working fine with Outlook on the Web and internally for the user. In addition, this was the only server hosting all the mailboxes and we could access them just fine with Outlook internally. As part of our troubleshooting, we disabled MAPI over HTTP in favor of the older RPC over HTTP connection method. Unfortunately, this provided the exact same result.
Fixing logon returned ecLoginFailure -2147221231
The remedy for us was to move all users to a new database. We tested this first by creating a new database and moving a single user over. When that user passed the Outlook connectivity test (and Outlook also connected externally) we moved all other users and system mailboxes to this database.
It is uncertain what was wrong with the original database. It was barely a week old and was the default database installed by Exchange. In any case, the fix was quite simple and it was easier to move the users than to continue troubleshooting for a root cause.
Have you run into this error? What was your solution? Drop a comment below or join the conversation on Twitter @SuperTekBoy.