We help IT Professionals succeed at work.

Mapi session exceeded the maximum of 32 objects of type "session"

38,324 Views
Last Modified: 2013-01-25
Hi,

I am getting the following on Small Business Server 2003, SP1 with Exchange patched at SP2, and for whichever user this error happens, that particular user will not b able to use outlook.
Event Type:      Error
Event Source:      MSExchangeIS
Event Category:      General
Event ID:      9646
Date:            9/4/2007
Time:            2:04:26 PM
User:            N/A
Computer:      C0SS01
Description:
Mapi session "/o=firstorganisation=Corporate/cn=Recipients/cn=xyzuserr" exceeded the maximum of 32 objects of type "session".

I've tried every registry hack that I've found on EE to workaround this, I've added the MaxOpenMessagesPerLogon key with Session set to 100, I've set "Maximum Allowed Sessions Per User" to 100, I've added a new key MaxObjsPerMapiSession with DWORD value Session set to 100.  I do not see anything in the registry for enabling TCPChimney, and the disabled command returns a "not found" error.

Any suggestions?  I was not planning on patching to SP2 because we are in discussions on a server upgrade.

Comment
Watch Question

Top Expert 2007

Commented:
Have you restarted the Exchange services? A simple reboot of the machine will clear up those sessions/connections....at the same time should make those reg changes stick.

Author

Commented:
Yes, I've restarted the services, and I've rebooted the server, the error comes back within a few minutes of users getting back online with Exchange.

Author

Commented:
Possibly relevant information:  the first time this error shows up inthe event log was approximately the same day that I uninstalled Symantec Mail Security for Exchange and moved spam filtering to a service provider.  There is no spam filtering software installed on any of the client PCs, only Symantec's corporate antivirus program.

Author

Commented:
increased point value to 500
Top Expert 2007
Commented:
Unlock this solution and get a sample of our free trial.
(No credit card required)
UNLOCK SOLUTION

Author

Commented:
Thanks, there is nothing in the registry regarding TCPChimney.  I'll try the permissions option. Still  sctratching my head...

Commented:
Unlock this solution and get a sample of our free trial.
(No credit card required)
UNLOCK SOLUTION

Author

Commented:
After re-doing everything documented on this issue, the problem resolved.  Perhaps I had a typo in my registry entries, I'm not sure, but the do-over fixed me.  Thanks for your help!

Commented:
I have the same issue and only found 1 of the solutions, the "MaxobjsPerMapiSession" fix and it doesn't seem to have fixed the problem.   WHo knows whatthe real fix is?

Commented:
Should we be concerned about why there are so many mapi sessions being created by individual users?  I understand this solution works around this issue but it doesn't get at the root problem.

Commented:
I DONT LIKE PLAYING WITH PERMISSIONS ON FOLDERS.....

I DONT LIKE PLAYING WITH REGISTRY ENTRIES IN ORDER TO UNDERMINE THINGS MICROSOFT DID TO MAKE THE SERVER FASTER AND MORE SECURE (kicking up the 'session' limit), THUS ELIMINATING THE SECURITY BENEFIT.....

I DONT LIKE GRANTING ACCESS TO ANYTHING THAT A USER WASN'T DESIGNED TO HAVE....

I think the answer on this thing is in the NDIS driver issue that aissim speaks about.
za_mkhIT Manager

Commented:
The problem here is not with the server itself but the client that is connecting to the Server. They have an underlying network issue that is causing them to get disconnected from the server. But the method in which they disconnect is not clean, so Exchange is unaware that the session is terminated. The next time said person connects, another 'session' is used up until the maximum is reached. That's when they can't connect anymore.

We had this issue with only one person in our organisation. I didn't want to change permissions / reg entries just to get this problem solved. In our case, the person had a dodgy wireless connection which meant that when she was connected via the VPN it created lots of 'orphan' sessions with the Exchange Server. Giving her a new wireless router, resolved our problem!

Commented:
Is there a permanent fix for this.
za_mkhIT Manager

Commented:
Yes, sort out the issue with the user/ user's computer that is experiencing the problem. I find that when this problem appears it only affects one or maybe two users. If all my users experienced it daily then I would say Microsoft would have to fix it or I could implement one the many workarounds (but reducing security - I feel) that would negate this problem.

Commented:
Just ran into the same issue at a client.  I ran through the article http://msexchangeteam.com/archive/2007/07/18/446400.aspx as aissim suggested and it worked like a charm.  The article says to update the NIC drivers to the version with the latest NDIS version.  The link provided in the article for the Broadcom drivers solved the problem with no other tweaks needed!
Jac SchroetenInfrastructure Specialist

Commented:
Interesting discussion. We appeared to have ran into a similar situation and my internet search brought me here (once again).
We recently moved one of our offices to a new location and for time being a dsl-line was installed untill the lines are delivered. Since the move all users from that office have the same issue, getting their mapi sessions exceeded to 32 and having no access to the exchange server anymore.

Our problem seems to be the temporary dsl which is not sufficient to support our 20 users at the office.
Thanks za_mkh, your adding put us on the right way. We're contacting the dsl provider now to have this solved.
Unlock the solution to this question.
Thanks for using Experts Exchange.

Please provide your email to receive a sample view!

*This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

OR

Please enter a first name

Please enter a last name

8+ characters (letters, numbers, and a symbol)

By clicking, you agree to the Terms of Use and Privacy Policy.