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Options to Send Emails using Microsoft 365

March 24, 2024March 24, 2024 Kent ChenMicrosoft

This is how to send emails from an app or device not named Outlook through the Microsoft 365 network. According to Mail Flow Best Practices, there are 3 options available. SMTP Auth If you can deal with Modern Authentication in the form of OAuth, this option provides you with the most reliable email delivery. And you do need a licensed […]

Email failed to deliver to certain domains with an SMTP protocol error occurred message

December 13, 2009January 24, 2023 Kent ChenMicrosoft

It happened lately in my office that emails sent to certain domains first got delayed and then failed with a SMTP error code 4.4.7 in the final NDR. Error code 4.4.7 usually indicates that the message in the queue has expired and usually the problem is on the receiving server. However, that is obviously not the case this time. Also […]