Title: Undeliverable: Fluent SMTP: Test Email – HTML Version
Last modified: April 16, 2023

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# Undeliverable: Fluent SMTP: Test Email – HTML Version

 *  Resolved [idealynx](https://wordpress.org/support/users/idealynx/)
 * (@idealynx)
 * [3 years ago](https://wordpress.org/support/topic/undeliverable-fluent-smtp-test-email-html-version/)
 * I just started receiving the error message below from the Microsoft 365 email
   account I send all FluentSMTP email notifications to. However, when I check Microsoft
   365 Defender for the message that was sent, there are no restricted entities 
   or quarantined messages. What am I doing wrong?
 * **Delivery has failed to these recipients or groups:**
 * [name@mydomain.com](https://wordpress.org/support/topic/undeliverable-fluent-smtp-test-email-html-version/kcrossley@mac.com?output_format=md)(
   withheld for security reasons)
   This message couldn’t be delivered because the
   sending email address was not recognized as a valid sender. The most common reason
   for this error is that the email address is, or was, suspected of sending spam.
   Contact the organization’s email admin for help and give them this error message.

Viewing 1 replies (of 1 total)

 *  Plugin Support [Amimul Ihsan](https://wordpress.org/support/users/amimulihsanmahdi/)
 * (@amimulihsanmahdi)
 * [3 years ago](https://wordpress.org/support/topic/undeliverable-fluent-smtp-test-email-html-version/#post-16664405)
 * Hello there,
   The error message is coming from the email sending service you are
   using and Fluent SMTP does not have anything to do with it. It seems like the
   email is blocked or reported hence the delivery provider cannot deliver the email.
   Please reach out to the delivery provider regarding the issue.
 * Thank you

Viewing 1 replies (of 1 total)

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## Tags

 * [email failure](https://wordpress.org/support/topic-tag/email-failure/)

 * 1 reply
 * 2 participants
 * Last reply from: [Amimul Ihsan](https://wordpress.org/support/users/amimulihsanmahdi/)
 * Last activity: [3 years ago](https://wordpress.org/support/topic/undeliverable-fluent-smtp-test-email-html-version/#post-16664405)
 * Status: resolved