I keep changing each of my email addresses to "let Outlook Decide" in order
to get rid of the "winmail.dat" attachments - but 2 months later - they all
have been switched back again. I have hundreds of contacts. Its always
the same ones that keep switching back to outlook rich text - and then these
people complain to me that they can't read my mail.

I have selected "Imap" as the preferred Mail format in Outlook options...

How can I rid my machine of this winmail.dat demon once and for all?

I wish there was a master switch - never send winmail.dat.....

Honestly, I am frustrated. Ready to dunk my machine in holy water.

Please help.