Step 1: Open your Windows Live mail program.
Step 2: Select the Home tab at the top right of your Windows Live Mail.
Step 3: Click the Outbox to the left. Find any emails that are not sending out. You will need to copy the content of the email and send it as a new email with the new account.
Step 5: Once you send the email again, you can delete the email in the Outbox. The error will go away after the sent email is deleted.
Step 6: During our research in finding out what causes this problem, we read many online forums that suggested the problem may be due to a conflict with an anti-virus program running on your desktop. While we don’t believe this is the case, you may want to try temporarily disabling any anti-virus programs (or related programs) and attempting to send the emails again.