On this page, you will find more information about the most common causes and most relevant solutions for the Yahoo! Mail error '554 5.7.9 Message not accepted for policy reasons'. Do you need help straight away? Visit our support page.
The Yahoo! documentation indicates that error code '554 5.7.9 Message not accepted for policy reasons' is caused by the following problem: "Your message wasn’t delivered because Yahoo was unable to verify that it came from a legitimate email sender.".
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