
554 Denied (XXXX): This message text refers to administrative blocking based on mail tactic patterns.
If you believe that the message is legitimate and should be delivered, contact the recipient and let them know what you are seeing and request that they Whitelist / Allow your sending address.
IPR/CIPR denials are based on the internally calculated reputation score of a single IP.
If you are receiving one of these errors, please contact the recipient of the message and ask them to open a service request with Mailscreen Support concerning the error.