[Typo3] direct mail completly transformed through microsoft exchange treatment

[Courcy Michael]

Hi list

My direct mail extension work really fine, except when the mail go 
through microsoft exchange.

After analyse of the body it seems that the content-type is changed from 
html to plain-text and the attached part are just cut off the mail body.

Does someone experience this already, and if yes, how did you fix this 
problem.

Thank you
Michael Courcy.