[Zope] problems with MailHost

Hi there, the ISP where my Zope Server is situated is using an MTA (Mercury 1.47 for Novell) that seams not to accept the mails generated by Zope's MailHost. It complains that the FROM: field is not valid. Now I have two questions: - Does anyone of you know a solution. - is there a mailserver (preferably in python) I could install on my NT box with which I can test what the difference between a Zope generated and a "normal" email is. Thanks for your help Robert www.redcor.ch don't mind my typos I see them neither