SBS POP3 Connector Encountered One or More Errors

SBS POP3 Connector Encountered One or More Errors

If you’re using the POP3 Connector feature of Windows Small Business Server 2011 to download emails to your local Exchange, the message you dread to see after hitting Retrieve Now in the Windows SBS POP3 Connector dialog box is the “POP3 connector service encountered one or more errors” message.

Upon looking in the event log, you wont see anything unless you drill down to the the SBS specific event logs:

  1. Go to Event Viewer
  2. Expand Applications and Services Logs
  3. Expand Windows Small Business Server 2011 Standard
  4. Click Microsoft Windows Small Business Server/Operational

Here you may be presented with an error along the lines of:

One or more messages (x) were left in the ’[email protected]’ account on the POP3 server ‘’ because they are larger than the maximum acceptable message size (the largest message is 26958505 bytes). You can either connect to the POP3 account and retrieve or delete the messages manually, or increase the maximum acceptable message size in Exchange Server.

Just Give Me The Fix!

Fortunately this is very easy to fix via the Exchange Management Shell, simply enter each of the entries below, replacing servername with your own SBS servers name and 30mb with the maximum size you want to allow (I choose 30mb as that is the largest workable size for general emails anyway).

As ever you use this script at your own risk, it comes with no guarantees and as with all powershell scripts can cause problems when used incorrectly!

Set-TransportConfig –MaxSendSize 30MB –MaxReceiveSize 30MB
Set-ReceiveConnector “Windows SBS Internet Receive Servername” –MaxMessageSize 30MB
Set-ReceiveConnector “Windows SBS Fax Sharepoint Receive Servername” –MaxMessageSize 30MB
Set-SendConnector “Windows SBS Internet Send Servername” –MaxMessageSize 30MB
Set-Mailbox “test” –MaxSendSize 30MB –MaxReceiveSize 30MB

For anyone in charge of a Small Business Server, I highly recommend the Windows Small Business Server 2011 Administrator’s Pocket Consultant

More Info

If you have any problems or want more indepth information, visit the technet article here:

Bob McKay

About Bob McKay

Bob is a Founder of Seguro Ltd, a full time father and husband, part-time tinkerer-with-wires, coder, Muay Thai practitioner, builder and cook. Big fan of equality, tolerance and co-existence.

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