I ran into an odd issue this morning. The only thing that I did was create a new EXUM contact which I can't see causing this but it's in the realm of possibility. When anyone creates a New Lync Meeting from the outlook clandar it displays without the standard format, example:
Join Lync Meeting (plain text)
https://meeturl.com/user/
When you click "Meet Now" and open up the option to send an e-mail invite it displays normally.
Could this be caused by my EXUM addition? Would an exchange transport rule be the case?
A blog post I found that might be related, http://hanytaha.wordpress.com/2012/01/11/how-to-add-custom-text-to-lync-meeting-invitation/
I'm also seeing differences in the "View Source" between the "New Lync Meeting" and the "Meet Now" email. Other searches indicate the <o:p> is word converting html to plain text.
Plain text.
Join Lync Meeting<o:p></o:p></p><p style='text-autospace:none'>
Join Lync Meeting</span></a><span style='font-size:14.0pt'