SMTP: Err Msg: 550 Addressee Unknown (100705)



The information in this article applies to:

  • Microsoft Mail Gateway to SMTP 2.1
  • Microsoft Mail Gateway to SMTP 3.0

This article was previously published under Q100705

SYMPTOMS

Versions 2.1 and 3.0 of Microsoft Mail Gateway to SMTP may display this error message:
550 Address Unknown

CAUSE

Thisindicates that the SMTP Gateway was unable to identify the recipient of the incoming message. This error message may occur if:

  • The recipient name of the address is not a valid Microsoft Mail user name. -or-

  • The domain name of the address not in the gateway's address map.
Ensure the recipient is a valid Microsoft Mail for PC Networks user name, and that the domain name received is in the address map table. You can modify or add entries to the address map in the Admin program (Gateway, SMTP, Address Map) to match the domain name being received.

Please refer to Microsoft Application Note "Configuring the SMTP Gateway and Domain Name Service (DNS)" and the version 3.0 "Microsoft Mail Gateway to SMTP Administrator's Guide," pages 34-40, for additional information.

Modification Type:MajorLast Reviewed:10/23/2003
Keywords:KB100705