Hi Chas

I have a client reporting that mail sent from Zope using a MS Exchange box as their Zope Mail Host never arrives.

Just tried using our Exchange server as the SMTP server for a MailHost (which works just fine with the other two 'real' SMTP servers I have access to, and sure enough, the mail never arrived. Looks like a real MS feature -- anyone else? BTW, the Exchange server works OK as an SMTP host from Outlook Express, which is the only 'standards-based' mail client I've got on this machine.

<guess> Maybe their exchange server is demanding that users authenticate before sending (this is configured with a checkbox somewhere in the Exchange Admin labyrinth, iirc). I don't know why this would cause a noticeable exception tho... </guess>

Don't think so, because I'm not authenticating when I use Outlook Express to send SMTP mail via the Exchange server -- I am on the same network though, but then so is Chas's client's machine. Cheers David