Select the user, and in the flyout that appears, click Mail. Also, be sure you're using the actual office365 email address for the account. Basic Authentication and Exchange Online – September 2021 Update Here are the mail settings you need: 1. You can find it by clicking on the profile button in Outlook365. There are two more PowerShell commands to run. Best Practices To Configure SMTP Relay Emails (Tested) After spending hours on this, I have found that the smtp host for the godaddy configured office 365 mail id is " smtpout.secureserver.net ". Configuring SMTP Authentication on Exchange Fix: Send-MailMessage - MorganTechSpace - Office 365 This is what a good log entry made by thunderbird looks like: