The error 0x80040115 was encountered while trying to communicate with the message store. An attempt to refresh the connection will be made. If not successful, the service will be shut down.
The ME166558 article is applicable to Exchange 5.0 but may provide a clue event for other versions.
From a suggestion in the newsgroups: "Change the registry setting so that you increase the number of threads available. For instance, changing it to 0x14 will provide a maximum of 20 threads." See also ME169686.
As per ME293288, this issue can occur on the Exchange Server computer that is running the Internet Mail Service if the header of a message contains malformed information.
ME322829 suggests that this behavior may occur because of a corrupted message, or because the Internet Mail Service is damaged.
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