MailMessage.Body limited?

[=?iso-8859-1?Q?Kai_Br=E4utigam?=]

Hi,

Sending an e-Mail(Html) with a large Body-Text gives me the strange problem
that only an empty e-Mail arrives. The Body-Text is not cut of or
something, it's just the html, head und body-Tags that are shown in the
source. A shorter Body-Text simply works fine.

Does someone has any idea what this could mean and knows a way how to fix
that problem?

Thanks in advance,
Kai