Ref: 17310014
Title: Sending to Mail Gateways via the _GATEWAY Username
date:  7/13/90

Copyright 3Com Corporation, 1991.  All rights reserved.

3+Mail and 3+Open Mail services support a _GATEWAY username
for mail gateways.  When mail is sent to a username not explicitly
in the name service, and the domain of that username is the same as
the _GATEWAY username, the Mail services will assume the mail is destined
for a foreign (non-3Com) mail service and will send it to the _GATEWAY
username for forwarding.

To set up a _GATEWAY user, create a new domain in the name service with
the same name as the foreign mail service and add a user named _GATEWAY to
that domain.  For example, to use 3+Reach/MCI:

1.  Create a domain named MCI.

2.  Create a user named _GATEWAY:MCI.

To use the gateway, send mail to a user in that domain.  For example,
to send mail to an MCI Mail user, you would address it to {UserName}:MCI.

3+Reach/MCI gateway retrieves mail through the user _Gateway:MCI,
then MCI Mail forwards the mail to the MCI mail user where
{UserName} must be an MCI Mail user.


To use a Gammalink FAX gateway, create a domain named FAXgate and create
a user named _GATEWAY:FAXgate.  To send mail through this gateway to a
remote FAX machine, address it to: {name \FAX:phone number}:FAXgate.

The Gammalink FAX gateway retrieves mail through the user _GATEWAY:FAXgate.
Then, based on the phone number in the username field of the original mail
message, the Gammalink FAX gateway will attempt to contact the remote FAX
machine and deliver the mail message.


If the conventions described above are followed, and mail is addressed
to a nonexistent user where the specified domain does not contain a _GATEWAY
user, the sender will be notified that the target username is invalid.

However, if a _GATEWAY user is present in the default domain of the
name service, all mail messages with no specified domain will be
transmitted regardless of their address.  As a result, all undeliverable
mail addressed to the default domain will be forwarded to the _GATEWAY user.
If the _GATEWAY user is an alias for _Gateway:MCI, the gateway will
attempt to forward the mail to MCI Mail.  It will then be rejected and
returned by the Gateway Postmaster.

If a _GATEWAY user is present in the default domain of the Name
service, delete the user.  This will enable 3+Mail to prevent users from
sending Mail to users not listed in the default domain of the Name service.
3+Mail client software will return the following error when a user is
addressed incorrectly:  "User name is invalid.  Send anyway  (Y/N)?
