Knowledgebase
How to fix the error 0x80040607 when sending mail with Outlook 2010
The most likely reason for receiving an error message containing the error code 0x80040607 when sending mails with Outlook 2010 is that you have not enabled SMTP authentication. The whole error message looks like this:
Send test e-mail message: An unknown error occurred, error code: 0x80040607
To fix this you have to enable outgoing (SMTP) server authentication. Start your Outlook, click on the File menu, then on the Account Settings button. On the new window that opens select the account and click on the Change button. On the next window containing your account information click on the More Settings button. Then on the smaller window that opens click on the Outgoing Server tab and mark the checkbox for My outgoing server (SMTP) requires authentication. The button for Use same settings as my incoming server should be marked by default. Then click on OK and test your account again.
For more information on how to set up Outlook 2010 to use your email account check out the respective tutorial or article.