[Zope] MailHost on Windows NT?

[abg@comco-inc.com]

I'm running Zope 2.3.2 (binary release, python 1.5.2, win32-x86) behind IIS
on a WindowsNT box.

Does anyone have any experience setting up MailHosts on NT? I keep getting
the following error when trying to send email:

Zope Error
Zope has encountered an error while publishing this resource.
Error Type: SMTPHeloError
Error Value: (501, 'Invalid Address')

It looks as though there's some sort of authentication issue between Zope
and my SMTP server, which is odd considering they're on the same box. Even
when I configure the SMTP server to allow all relaying, Zope can't get
through.

Any suggestions will be greatly appreciated.

Aaron