Knowledge Base

SMTP: Err Msg: Warning No Return Path

Article ID: 107087

Article Last Modified on 10/30/2006

APPLIES TO

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

This article was previously published under Q107087

SYMPTOMS

The Microsoft Mail Gateway to SMTP displays this warning:

WARNING No return path
[tx] 250 Sender OK

CAUSE

The name provided in the "mail from" received by the sending host is incomplete or contains a null value:

[rx] mail from:<>

RESOLUTION

None necessary: this message is informational only and requires no action by the Mail Administrator. The Gateway continues to process mail.

MORE INFORMATION

The example below shows an address without a beginning "<" and an ending ">". This log file was created using the undocumented -CD option which tells the Gateway to display debug information.

>Incoming SMTP connection from [192.245.59.139]
[tx] 220 All set, fire away
[rx] hello fake.host.com
[tx] 250 Hi there, pleased to meet you
[rx] mail from:jdoe
>WARNING No return path
[tx] 250 Sender OK

Additional query words: 2.10 3.00 2.1 3.0 warning

Keywords: KB107087