SMTP: Err Msg: WARNING Incoming SMTP Mail From Unknown Host

Retired KB Content Disclaimer

View products that this article applies to.

This article was previously published under Q105130

Expand all | Collapse all

SYMPTOMS

Versions 2.1 and 3.0 of Microsoft Mail Gateway to SMTP may display the following message in the SMTPGATE.LOG file, and/or the Gateway PC screen:

[rx] HELO
<time> WARNING Incoming SMTP mail from unknown host

Note: Using the undocumented switch -CD with the SMTP gateway provides debug information on the gateway screen and log file when full logging is turned on with -GACSY and -LACSY command line options.

Back to the top

CAUSE

This warning indicates that section 3.5 of RFC 821 (the "HELO" command is used to identify the sending host) has been violated. The correct syntax should be:

[rx] HELO hostname.domain

Back to the top

RESOLUTION

No action is required. The SMTP Gateway will continue to process mail. The message is merely for your information.

For more information refer to RFC 821.

Back to the top

APPLIES TO

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

Back to the top

KB105130

Back to the top

Retired KB Content Disclaimer

This article was written about products for which Microsoft no longer offers support. Therefore, this article is offered "as is" and will no longer be updated.

Back to the top