Your message couldn’t be delivered because you weren’t recognized as a valid sender

by Abou Conde
Posted on March 13, 2019
Exchange

If a user continuously sends emails from Office 365 that are classified as spam, they will be restricted from sending any more messages outbound. The user will be listed in the service as a bad […]

by Abou Conde
Posted on January 18, 2019
Office 365

With message recall, a message that you sent is retrieved from the mailboxes of the recipients who haven’t yet opened it. You can also substitute a replacement message. For example, if you forgot to include […]

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Cloud and Datacenter Management

Office 365

Your message couldn’t be delivered because you weren’t recognized as a valid sender

How to Recall or replace an email message that you sent