Fix "Openmsgstore failed" error in Exchange server

In Exchange server, Openmsgstore is a method related with MAPI working interface mainly used to open a message store. This method results to a reference which is passed in Imsgstore object in order to have further access to the items stored in the mailbox. But any problem during this process can lead to errors like Openmsgstore failed which appears after every minute. Further you will get the following event log description for the error:

“The Microsoft Exchange Server computer is not available. Either there are network problems or the Microsoft Exchange Server computer is down for maintenance. The MAPI provider failed. Microsoft Exchange Server Information Store ID no: 8004011d-0526-00000000”


The above encountered error occurs when Information Store (IS) is not running or when the mailbox store is unable to mount. There can be a number of reasons behind not running of Information Store such as:

  • If an expired version of Exchange server is being used
  • Partition on which IS files are stored is less than or equal to 10MB
  • When Information store is in dirty shutdown state or is corrupt


First of all, you need to make sure that the IS is running. For this go to Services in order to know the status of IS if it is running or not. If yes, then check the mailbox store is mounted and if not then restart the store. Perform the below steps to resolve the mapi call openmsgstore failed error:

Make use of an activated version of Exchange server

Ensure that the IS partition is greater than 10MB

Run Eseutil/p command to repair the corrupted Information store. It will delete the corrupted data and thus causes data loss situations. But if does not work, then you can use Edb repair tool that is highly capable to repair the damaged database efficiently by involving only few simple steps.