We have a custom smtp server that checks several limits
before allowing a user to send an email, this checks is done
based on the user that authenticated on the smtp "smtp-auth"

I would like to force all email sent from the Webmail to go through
this smtp, I found the "MTA webmail" in the server configuration page
with that I can redirect the webmail users to my smtp server, but the
webmail DO NOT authenticate the user.

Any idea on how to do that or implement this?

I looked at the
maybe I could change the Transport.send(mm) to do an authenticated send
but I am still missing the user password to authenticate

Thanks for any help