I had a client recently who had a really strange Exchange server issue. The initial symptoms were:
- No mail flow
- Unable to send or receive email
Nothing too usual for these symptoms. Any sort of serious Exchange issue will be accompanied by these two things. But closer examination also showed that all of the services for Exchange were started and running properly.
A closer examination showed that while emails from Outlook seemed to leave the Outbox properly, the same emails from OWA sit in the drafts folder with no option to continue editing or to send.
In looking at the security log, there are repeated failure event with the ID 4625, indicating that the Health Mailbox failed to login properly. This, along with the other symptoms, indicates corruption in the Health mailboxes themselves. But, the good news is that this is easy to fix. All you have to do is delete the Health mailboxes and restart the Health Monitoring Service.