I receive the error message 'Constant send error' when using Outlook. Messages do not appear in 'sent' or 'outbox' folders.

Hi,

What is the account type in your Outlook? Exchange, IMAP or POP?

Please make sure the Account Settings are correct for your account, such as your smtp server address and type of encrypted connection. You can get the information from your email service provider.

If you have verified the account settings, since I have never seen the error message before, would you please detail what step you performed before the issue occurred and the screenshot of the error message? To protect your private information, please send the information to our email address:

ibsofc@microsoft.com

Regards,

Melon Chen
TechNet Community Support