[Zope] Dtml-mime & Groupwise

Hi All, Currently I'm writing an application which sends HTML mails to a recipient. The problem is that the recipient uses Groupwise and whem using <dtml-mime type="text/html"> the messages is recieved as an attachment. Has anyone succeeded to write a html mail which is recieved correctly bij Novel Groupwise client? Greetings Ralph van den Houdt