Exchange error:
Your server administrator has limited the number of items you can open
simultaneously. Try closing messages you have opened or removing
attachments and images from unsent messages you are composing.

Possible solution 1(from version 5.0.0.7):
-Use Primary key File storage
http://support.geniusconnect.com/Posts/t555- 
-Set Outlook to cached mode

Enable caching for Public Folder (when synchronizing public folders)
http://www.msoutlook.info/question/129 


Possible solution 2:
Inactive Outlook connections to the Exchange server may not be cleaned up:
http://support.geniusconnect.com/Posts/t511 

Possible solution 3:
recommended by MS Support:

On EXCHANGE SERVER!
Disable the session limit by setting the following value to 1.
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSexchangeIS\ParametersSystemValue: Disable Session Limit

OR

See:
http://technet.microsoft...m/en-us/library/ff477612 (v=exchg.141).aspx

We have been getting exchange connection error since migrating from exchange 2007 to exchange 2010 (Version14.2 - Build 247.5).
Genius Connect is installed on Windows 2008 R2 64 Bit Outlook 2010 64 Bit Version 14.0.6129.5000 (We upgraded to work with 2010. It was on XP with outlook 2003)
We are syncing to SQL 2008.
Genius configuration has been the same for 3 years we have a licensed version.
We are synchronizing 19 public contact folders and 50 mailbox contacts about 14,000 contact records total.

We have given the account administrative privileges and added it to a throttling policy with no restrictions.

We set the following registry keys on both exchange mailbox server and the front end servers.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\MSExchangeIS\ParametersSystem\MaxObjsPerMapiSession] "objtMessageView"=dword:00004e20
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\MSExchangeIS\ParametersSystem\MaxObjsPerMapiSession] "objtMessage"=dword:00004e20

The translation of the dword is 20,000 which is up from the default 200

I can get through at least one cycle but eventually get the following errors and I have to log out or restart:

Error log from Genius Connect computer:
GeniusConnect error: Sync initialization error: Microsoft Outlook:Your server administrator has limited the number of items you can open simultaneously. Try closing messages you have opened or removing attachments and images from unsent messages you are composing. [GeniusConnect version:501301 Unicode 64 bit].

Error log from Exchange:
Mapi session "e022c673-f23d-4756-a166-93d68f560d09: /o=HBSR/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=CRM Admind27" exceeded the maximum of 20000 objects of type "objtMessage".

Hello,

are you using primary key File storage or Outlook item storage ?
http://support.geniusconnect.com/Posts/t555-  )

http://support.microsoft.com/kb/2297543 

This problem can be also related to multiple machines/devices connecting to the same mailbox(es). Some session limits are per IP address, many are per authenticated session so if (for example) your mailbox works quite happily on one machine, when you leave Outlook running on other PC (connected to the same mailbox) you may easily exceed your available system resources and you will see session limits errors.

Exchange Managed Store Session Limits (MoMT)

In environments with many shared mailboxes, the issue may also be caused by Exchange Managed Store session limits, not by Outlook or GeniusConnect.

All modern Exchange versions (2013, 2016, 2019) use the Managed Store architecture and enforce a limit on MAPI on the Middle Tier (MoMT) sessions.
The default value is:

- 32 sessions per user per mailbox database

When a service account opens many shared mailboxes, Exchange counts each mailbox as a MoMT session. After the limit is reached, Exchange starts rejecting additional sessions, which can result in:

- “The administrator has limited the number of items you can open simultaneously”
- Missing mailboxes in Outlook
- Sync failures after adding more mailboxes

Administrators can increase this limit (for example, from 32 to 200), and this typically resolves the issue immediately. This is an Exchange‑side configuration, not related to GeniusConnect.


How to increase Exchange Managed Store (MoMT) session limits

To raise the default MoMT session limit (32 sessions per user per mailbox database), increase the connection limits on the mailbox database or organization level:

Increase per‑database limit
powershell

Increase organization‑wide MAPI connection limit
powershell

Apply changes
powershell

This raises the Managed Store session capacity and prevents session‑limit errors when many shared mailboxes are opened by the same account.