No idea what's going on here. The trouble with this "solution" is that each
implementation is going to be completely different and each with its own
problems and nuances.
The solution I created initiallaly was also for an Exchange mail environment
with Domino for web-apps. The only way I found to get it to work as expected
was to get the Notes server to connect to the SMTP socket [<i>on the Exchange
server</i>]. This way you should find that it all behaves as it would if you
were sending a mail normally from Outlook or whatever. Using the Notes/Exchange
Gateway seemed flawed to me.
If you still have problems try sending mail to multiple recipients one at a
Either way be sure to let us all know what you find....