Event ID 3231: Could not get a MAPI session from the session pool

Problem

Event ID 3231: Could not get a MAPI session from the session pool

Error Message

Event error 0x81002746 :Could not get a MAPI session from the session pool

Cause

This error can occur while starting the Archiving or Journaling service . When the Archiving or Journaling service starts, it attempts to connect to the Archiving or Journal mailbox it is configured to process. An error is logged if it was unable to log in to the mailbox successfully.

This error is so critical that the Archiving or Journal service shuts down automatically. Even the synchronization of mailbox properties can result in such an error.

This issue is most likely due to an underlying Exchange connectivity issue.

1. Exchange server may be down.
2. Messaging Application Programming Interface (MAPI) connectivity error with Exchange.
3. Exchange is unable to resolve the system mailbox.
4. System mailbox may be  hidden in the Global Address List (GAL).

Solution

1. Stop all  Enterprise Vault services
    
2. Open SQL Enterprise Manager or SQL Server Management Studio.
    
3. Click on the New Query button in the toolbar.
    
4. In the New Query window, type and execute the following SQL query:
   USE EnterpriseVaultDirectory;
SELECT SystemMailbox FROM ExchangeConnectionPoints;
    
5. Verify the value on each SystemMailbox column in each output and confirm there is no space after SMTP as shown in this example:
   
   Incorrect:
   smtp:    user@domain.com
   
   Correct:
   smtp:user@domain.com
   
   smtp:user@domain.com is the email account will be the account that is listed in the SystemMailbox column.
   
   If the SystemMailbox column has a space, continue with the next step.
    
6. Note the SystemMailbox column for each table and run the following SQL query command:
   
   USE EnterpriseVaultDirectory;

UPDATE ExchangeConnectionPoints SET SystemMailbox = 'Corrected_SMTP_Email_Address'
WHERE SystemMailbox = 'Incorrect_SMTP_Email_Address'
   
   Note: Replace the values from Corrected_SMTP_Email_Address and Incorrect_SMTP_Email_Address using the correct SMTP email address and the incorrect email address from each table.
    
7. Start all Enterprise Vault services.