Hi, We are using Exchange 2007 SP3 Rollup 4 on 2008SP2 with current MS updates. Exchange is configured with 2 CAS (CAS and Hub) and 2 CCRed Mailbox servers. We are having 2 issues which seems like the mailbox server is going inactive after a period of time and requiring an intial nudge to start performing correctly again: 1) If no one uses the OWA for 2-4 hours, after successfully logging in, they will get a 'You do not have permission to open this mailbox'. Hitting refresh will fix this issue and everything is great as long as people keep periodically hitting the OWA. 2) Our first person in in the morning that tries to send emails gets 'This message could not be sent. Try sending the message again later, or contact your network administrator. Error is [0x80070005-00000000-00000000].' When they try to send email again everything works fine and Exchange behaves correctly for the rest of the day. There seems to be no pertinent errors in the Application or System logs on any of the servers. I'm currently trying to verify the Security logs for any possible errors that might apply. The OWA problem we have been having for awhile, problem #2 only started after I forced cached mode to everyone (we use Outlook 2003-2010). Exchange behaves correctly during this time receiving outside email. Thanks for any help, Gordon

Have you checked if there is a 3rd party LAN driver application that is managing the LAN card's state?Miguel Fra / Falcon IT Services Computer & Network Support, Miami, FL Visit our Knowledgebase and Support Sharepoint Site

Hi Gordon, Have you tired looking at IIS logs? this is usually located in the Inetpub folder. let us knowZ-Hire -- Automate IT Account creation process ( AD / Exchange / Lync ) Z-Term -- Automate IT account termination process ( AD / Exchange )

Thanks for the responses, Mailbox servers are on two HP C-Class blades, BL260c G5s, NIC drivers were actually out of date (SIM looked good so I didn't notice); I'll be updating them when I can. Virtual connect is two revisions out. I looked at the IIS logs and everything looks ok (anything specific I should be looking for?). I can see one of my users that got the 'You do not have permission to open this mailbox' login at 6:13AM, logoff and then login again 5 minutes later when she sent emails. Thanks again, Gordon

can you try using OWA typing the physical node name instead the virtual node. may be something wrong at the NLB

Hi If ad account is not verified by DC. You will receive your two error information. You can test owa by CAS ip address without NLB and observe your DC.

I had previously removed NLB and turned our 2nd CAS server off to aid in testing. We have the same issue regardless of whether we hit OWA from the outside or inside of our network, regardless if we use outside DNS or inside AD name directly (I haven't tried just IP). I reproduced the OWA error this morning and finished going through the security logs on the CAS server and both mailbox servers. There was no audit failure of any sort at that exact time of the error on any of the servers.

I have not used OWA 2010 but I would ask , when you logon to OWA do you use Private Computer or Public computer option logging in?

Updating the nic drivers didn't seem to fix the problem. I ended up creating an html page that autologged into owa as a test account. I setup a 1 hour recurring scheduled task on a cas server to run a batch file that killed all ie processes and then ran the html page to login to owa. This seemed to fix issue #1 for me. Issue #2 is semi-resolved with me taking our earliest morning user out of cached mode. Now her first email just goes to Outbox and she has to manually resend it and then everything works fine. I think I'll just live with this current situation until I can get our agency migrated over to Exchange 2010 (hopefully 6 months). Thanks for all the help everyone.