Re: TURN and disconnected SMTP with dynamic IP addresses

["Jack De Winter" <jack@xxxxxxxxxxxxxx>]

Was talking with Paul Hoffman from the IMC, and we came up with
a manner to make ETRN work in a failsafe mode.

Assume that we come out with an extra parameter for the ETRN command
so that:

C: ETRN <node> <key>
S: 250 OK

causes a connection to be forced to the given node.  When the connection
is established, we add an extra part of the EHLO parameters so that we
would receive:

...
250-ETRN
250-ETRNID <key>
...

when we establish the connection.  

In this manner, the remote host would be using the same mechanism to 
start the connection to the transient local address.  When the connection
is established, the key that was sent in the ETRN command can be compared
against the key provided.  If they do not match, you can probably assume
that you are not connected up to the host, and the transient host's
IP address may have changed.

thoughts? this should address the problems presented thus far.

regards,
Jack
-------------------------------------------------
Jack De Winter - Wildbear Consulting, Inc.
(519) 884-4498		http://www.wildbear.on.ca/

Author of SLMail for 95 & NT (http://www.seattlelab.com/)