{4}: The e-mail message was rejected by the recipient's e-mail system. This code indicates an incorrect e-mail address was used. However, it may also be returned if the submitted e-mail message is considered spam. Review the extended reason in the diagnostic part of the received non-delivery report.
The e-mail message format was corrupted and could not be delivered. The sender should try creating a new message and sending ...
The e-mail message was corrupted or altered, and the recipient e-mail system that is responsible for validating or decrypting ...
The e-mail message was damaged or altered. As a result, the recipient's e-mail system that is responsible for validating ...
The e-mail message was rejected by the recipient e-mail system. This code indicates a generic incorrect e-mail address issue. ...
The e-mail message was rejected by the recipient's e-mail system. This code indicates an incorrect e-mail address was used. ...
The e-mail system is experiencing delays. Several messages may be affected. The system will continue trying to deliver this ...
The e-mail system issued a protocol command with invalid arguments. The sender can try sending the e-mail message again later. ...
The e-mail system limits the number of recipients that can be addressed in a single message. Send the message multiple times ...
The e-mail system limits the number of recipients that can be addressed in a single message. Send the message multiple times ...