GUI Error - Message refused

1. 554 – message refused.

1.1 The mail server was rejecting the address because it was bad. A transcription error allowed an relatively unnoticeable character into the address.

1.2 Secureserver.net - Your access to this mail system has been rejected due to the sending MTA's poor reputation. If you believe that this failure is in error, please contact the intended recipient via alternate means.

2. 554 – Transaction failed.

2.1 Nowadays SMTP status 554 is in most cases returned when the recipient server believes your email is spam or your IP address or ISP server has been blacklisted on one or more.

2.2 With Yahoo, on the other hand, this usually means the email address does not exist or has been disabled.

2.3 With IBM’s Lotus Domino this is either a Domino bug or a Disk Full error.