[Guy Harris <gharris@xxxxxxxxx>]

Nozell, Paul wrote:

> The connection breaks just after the host submits the MAIL FROM: 
> command,

...and then the host drops *its* side of the connection by sending a 
FIN, so the SMTP server has no reason to wait for anything else to be 
sent to it, and drops its side of the connection after sending a reply 
to the MAIL FROM: and then trying to read from the connection and seeing 
the end-of-stream.  I have no idea why the SMTP client is doing that; 
you'd have to answer that one.

Try using "Follow TCP Stream" on one of the packets in that session, 
which has a side-effect of filtering the display to show only the 
packets in that session.