In our network, some users cannot connect to either Exchange Server 2007 or Outlook Web Access while others are able to connect to both. On one computer, the error occurred after the user ran the AVG anti-virus update. Some computers return this error message "Task 'Microsoft Exchange Server' reported error (0x800401 ID): The server is not available." Thanks, in advance, for your help!

2 Answers 2


The problem was caused because our firewall was somehow configured to act as DHCP server, in addition to the regular DHCP server we had. As a result, the computers that received their IP address from the regular DHCP server worked fine. Those that received their IP address from the firewall didn't work!


The same thing happened again today. Some users were able to connect to Exchange and OWA to send/receive emails while others were not able to do so. I checked the firewall to see if it was acting as the DHCP server and that wasn't the case. Upon further investigation, I found that one of the three mailboxes in Exchange Server 2007 was dismounted. I copied the database and the logs and mounted the database. And then I was able to send/receive emails from all users. My friend who helped me suggested that I run a backup immediately and run the "Eseutil /p" command to repair the Exchange database.

  • It would be wise to find out why the database dismounted, since databases don't just dismount for no reason. Additionally, eseutil /p is something you should use as a last resort on a corrupted database, not just because it dismounted. Also, once the repaired database is mounted you should move all mailboxes off that store ASAP because it cannot be trusted. Oct 19, 2011 at 20:08

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