SMTP: Explanation of FROM Field wit

 Last reviewed: October 20, 1997
Article ID: Q98067
2.10 3.00 MS-DOS kb3rdparty

The information in this article applies to:

  • Microsoft Mail Gateway to SMTP, versions 2.1 and 3.0

If a message cannot be successfully delivered, the Microsoft Mail Gateway to SMTP or Microsoft Mail may generate a message from "Network/Postoffice/Postmaster," advising the sender of a problem.

These messages can sometimes get bounced back and forth between Microsoft Mail and the SMTP environment if the sender or recipient names are invalid. To stop this bouncing phenomenon, (also called looping or ping-pong) the SMTP Gateway replaces "Network/Postoffice/Postmaster" with "<>" (Greater- than and Less-than signs).

The message is not returned to the Microsoft gateway because the SMTP host does not have a valid address to send the mail message back to; it is sent to the administrator for the Microsoft gateway.

Example

OUTGOING MESSAGES: 

  If an outgoing message is from:
    Network/Postoffice/Postmaster

  The SMTP Gateway replaced it with:
    <>
INCOMING MESSAGES: 

  If an incoming message is from:
    <>

  The SMTP Gateway replaced it with:
    Network/Postoffice/Postmaster

Additional reference words: 2.10 3.00
KBCategory: kb3rdparty
KBSubcategory: MailGWSMTP

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Last reviewed: October 20, 1997
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