HELP!

When I send emails, all the recipients get is content-transfer-encoding..... Basically, i can receive html/mime, but when i send emails, it's received in code (ie: This is a multi-part message in MIME format.
------=_NextPart_000_0011_01C95E9F.A8850270
Content-Type: multipart/alternative;
boundary="----=_NextPart_001_0012_01C95E9F.A8850270" etc. etc.)

This happens to all my contacts i send to..... Something is missing, but what?
I've tried a system restore & fiddled in options, but no joy.

Can anyone help?