Tuesday 21 June 2011

Outlook Error – Cannot open your default e-mail folders. You must connect to Microsoft Exchange with the current profile . . .

We ran the gamut of trying to figure out the following error:


Microsoft Outlook

Cannot open your default e-mail folders. You must connect to Microsoft Exchange with the current profile before you can synchronize your folders with your Outlook data file (.ost).



Microsoft Outlook

Cannot open your default e-mail folders. The file C:\Users\UserName\AppData\Microsoft\Outlook\UserEmail@Domain.ca – First.ost is not an Outlook data file (.ost).

We tried everything from recreating her Outlook Profile, removing the OST file just in case it was corrupted, a number of combinations including the aforementioned steps along with others, and finally flattening her local profile and starting fresh.

It was not until we signed into a desktop OS VM with the user’s credentials after they mentioned that Outlook threw the same error for them when signing into a spare laptop that it became apparent that we were dealing with a server problem.

There was no clue that the problem was with SBS 2003 and Exchange 2003 because no other users were complaining about a Disconnected Outlook.

After combing through the logs on the SBS 2003 server we turned up the following:


Event ID: 9646 MSExchangeIS

Mapi session “/o=DOMAIN/ou=first administrative group/cn=Recipients/cn=Username” exceeded the maximum of 32 objects of type “session”.

Searching for this error brought us to the following KB article:

We needed to add the following registry key and restart the Information Store on the problematic server:


    1. Click Start, click Run, type regedit in the Open box, and then click OK.
    2. Locate and then click the following registry subkey:


    3. If the Maximum Allowed Sessions Per User entry does not exist, do the following:
      1. On the Edit menu, point to New, and then click DWORD Value.
      2. Type Maximum Allowed Sessions Per User as the entry name, and then press ENTER.
    4. Right-click the Maximum Allowed Sessions Per User entry, and then click Modify.
    5. Click Decimal, type the value that you want to set in the Value data box, and then click OK.
      1. We used the value of 128.
    6. Exit Registry Editor.
    7. Click Start, click Run, type services.msc in the Open box, and then click OK.
    8. Click the MSExchange Information Store service, and then click Restart Service.

We confirmed that the Information Store restarted properly and our stores were mounted. We then started Outlook on the user’s system and were finally greeted with their mailbox!

Note that the user was using OWA when the problem started so it did not become apparent that the problem was on the server until _well_ into this troubleshooting process.

Philip Elder
Microsoft Small Business Specialists
Co-Author: SBS 2008 Blueprint Book

*Our original iMac was stolen (previous blog post). We now have a new MacBook Pro courtesy of Vlad Mazek, owner of OWN.

Windows Live Writer


Anonymous said...

I have same problem. Because my problem not issuee.

Anonymous said...

Thank you, your solution worked perfectly!

Zoli said...

I had a same problem and your article helped me to solve it. Thank you.

Matt Muller said...

Thanks, this helped tremendously.

Anonymous said...

Thanks! This really worked out for me:)

Anonymous said...

Yep, this resolved my issue too.

Great step by step instructions

Much appreciated!

Anonymous said...

Thank you!!

Michael M+ said...

I like this. It worked just perfectly. No guess work here!

gareth said...

Worked for me, thanks!

Anonymous said...

Anyone try this on Exchange 2010? I am having the same issue with one user.

Anonymous said...

GREAT SOLUTION!!!!! This worked perfectly for me. Thank you!

Anonymous said...

Hi Anonymous,
Did you find a solution to yours as we are on Exchange 2010 and have a similar issue ?

Anonymous said...

I had such an issue today, Exchange 2013.

After hours of troubleshooting... determined it was it was due to the MAPI limit - likely caused by Outlook addins/ open Outlook sessions.

Quick fix without changing Exchange Server registry entries - close out the Outlook client.
Test on new machine and then reopen the old client.