HTML emails being converted to plain text

We have a user who sends all of her emails out in HTML format, but when people receive them they are in plain text. This is causing the logo and email address in her signature to be displayed incorrectly. We are using Office365 so there aren't really any MIME settings that I can directly control.
Is there anything I can do to try and correct this problem or should I be on the phone with Mircrosoft?

Thanks in advance.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Simon Butler (Sembee)ConsultantCommented:
Check if it happens through OWA as well. If so it has to be something on the client.
If you strip the signature, does it still happen?

Vasil Michev (MVP)Commented:
First ot all, ask her to test in OWA, just to make sure it's mailbox related issue, not client one. Also, check for any rules, or better yet, run Outlook with the /cleanrules to delete any rules set on client and server side.

As for the MIME settings, you can control these for external contacts and remote domains, no option to control it for internal as far as I know.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.