Andrew , Jens,
I found the option in Hotmail and it works.
The strange thing is that I had activated the option "extra" in the server-manager panel to "strip certain mimetypes".
When I use Outlook Express to mail to the mailinglist and use rtf or html, no error occurs. Ezmlm just strips the html and rtf specific things. Why doesn't ezmlm just strip the rtf- or html specific things from Hotmail mails?
Rien