You are describing an HTML or RTF message. For HTML, you can set the
HTMLBody to your fully tagged HTML content. Embedded images take a little
more effort; see http://www.outlookcode.com/d/code/htmlimg.htm
For RTF format messages, see http://www.outlookcode.com/d/formatmsg.htm for
various approaches.

Signature
Sue Mosher, Outlook MVP
Author of
Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx
>I need to create a message with a quite complex body format (in term of
>fonts, pictures, signatures, logos and so on) and sent it using Outlook
[quoted text clipped - 13 lines]
>
> Mario