Event ID - 4120

Event Id4120
SourceMSExchangeIMC
DescriptionIn the process of creating a notification of delivery failure to the sender of a message, an error occurred causing the notification to be aborted. The sender is not informed that his original message failed to be delivered.
Event InformationAccording to Microsoft:
CAUSE
This problem can occur if the message has more than 32,766 (0x7FFE in hexadecimal numbers) recipients defined. The Internet Mail Service uses Messaging Application Programming Interface (MAPI) to create non-delivery report (NDR) messages, and attempts to add the recipients to an NDR message that MAPI is creating. MAPI uses the Emsmdb32.dll file to communicate with the information store, and the Emsmdb32.dll file has a limit of 32,766 recipients defined for the number of recipients on a single message.
RESOLUTION
A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem.
Click the link given below to obtain the latest service pack and fix.
Reference LinksInternet Mail Service Does Not Generate Non-Delivery Report Message If Number of Recipients Exceeds 32,766

Latest service pack and Fix

Catch threats immediately

We work side-by-side with you to rapidly detect cyberthreats
and thwart attacks before they cause damage.

See what we caught

Did this information help you to resolve the problem?

Yes: My problem was resolved.
No: The information was not helpful / Partially helpful.