Solution by Anonymous

To add a registry key that limits the maximum number of resources that a MAPI client can use at the same time, follow these steps:
Click Start, click run, type regedit, and then click OK.
Expand the following registry subkey:
\\HKEY_LOCAL_MACHINE \SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem
Right-click ParametersSystem, point to New, and then click Key.
Type MaxObjsPerMapiSession, and then press ENTER to name the new subkey.
Right-click MaxObjsPerMapiSession, click New, and then click DWORD Value.
Type Object_type, and then press ENTER to name the object.

Note Object_type is the name of the object type in the error message that is mentioned in the "Symptoms" section. For example, type objtMessage, and then press ENTER.
Right-click Object_type, and then click Modify.
In the Value data box, type the number of objects that you want to limit this entry to, and then click OK. For example, type 350 to increase the value for the objtMessage object. The default value is 250.