Receiving a "554 Message not allowed - " error
"554 Message not allowed - "
- Indicates that your email was not accepted because the message in question may contain characteristics that Yahoo Mail will not accept for policy reasons.
- For example, it is against Yahoo Mail's policy to accept messages with malicious content or manipulated header information, such as:
- A falsified origination point.
- An altered sending date.
- A forged email address.
- If you're the administrator for the mail server in question, we ask that you review outgoing messages for potentially objectionable content or practices.
- See our Best practices for bulk mail senders and postmasters for sending to Yahoo! Mail for additional information.
Note: Yahoo is unable to disclose specific information regarding our filtering practices.