Unknown Error 0x80041004" when sending mail

Outlook users report that when attempting to send mail, they receive the error: "Task 'Kerio Mailserver - Sending' reported error (0x80041004): 'Unknown Error 0x80041004'". Mail remains in the Outbox.

This can occur when the Kerio Outlook Connector profile in Outlook is set to use a "Default Delivery Location" which is not the Kerio Outlook Connector Store. For example, you may have it set to "Personal Folders". For the Kerio Account, the data store should always be the Kerio Outlook Connector Store.

  1. Go to Tools > E-mail Accounts. The "Deliver new e-mail to the following location" setting should be "Kerio Outlook Connector Store". It should not be "Personal Folders" or any other setting.
  2. Restart Outlook.
  3. Delete mail files in all Outboxes. This includes Personal Folders if you have them.

Sending mail should now work normally.