David Verbeek wrote:

i tried it with 2 different ones:
one correspondent has Outlook Express, the other has Hotmail

Hotmail isn't a mail client. Perhaps you mean he's using the web interface
to Hotmail. IN each case, it's still pointing to you using Rich Text format
because only Outlook can decode Rich Text.

no, that's not the case

How do you know? If the recipients you are mailing are in your Contacts
folder, even if you are choosing a format other than Rich Text in the Mail
Format options, that can be overridden by a setting in the contact's
records. Open each contact and double-click the e-mail address and examine
the "Internet Mail Format" drop-down. Make sure it says, "Let Outlook
decide the best sending format" and not "Send using Outlook Rich Text
Format".
--
Brian Tillman