A general mailbox access error occurred while receiving email error appears when testing and enabling a mailbox in Microsoft Dynamics 365

This article provides a solution to an error that occurs when you attempt to test and enable a mailbox in Microsoft Dynamics 365.

Applies to:   Microsoft Dynamics 365
Original KB number:   4092736


When you attempt to test and enable a mailbox in Microsoft Dynamics 365, you receive the following error:

"A general mailbox access error occurred while receiving email. Mailbox <Mailbox Name> didn't synchronize. The owner of the associated email server profile <Profile Name> has been notified.
Email Server Error Code: Socket returned exception TimedOut."

If you select the Details section, you may also see more details such as the following text:

"Error : System.Net.Sockets.SocketException (0x80004005): A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond <IP Address><Port>
at System.Net.Sockets.TcpClient.Connect(String hostname, Int32 port)
at Microsoft.Crm.Asynchronous.EmailConnector.Pop3Client.Connect()"


This error can occur if the port values within the Advanced section of the email server profile aren't correct.


  1. Navigate to Settings, Email Configuration, and then select Email Server Profiles.

  2. Open the Email Server Profile that is used by the mailbox meeting this error.


    You can also select the name of the Email Server Profile within the error message. It appears as a hyperlink which will open the correct Email Server Profile record.

  3. Select Advanced.

  4. Verify the Incoming Port and Outgoing Port values and then select Save.


    Refer to the documentation from your email provider for the correct ports to use when connecting to the SMTP service. For Gmail, the incoming POP3 port is 995 and outgoing SMTP port is 587.

  5. Select Mailboxes and then select the mailbox that received the error.

  6. Select the Test & Enable Mailboxes button.

  7. After the tests complete, open the mailbox record and view the Alerts section if the results don't appear as Success.

Third-party information disclaimer

The third-party products that this article discusses are manufactured by companies that are independent of Microsoft. Microsoft makes no warranty, implied or otherwise, about the performance or reliability of these products.