We seem to be having a rather very odd, and intermittent issue. 

Our COO keeps sending emails with a copy and paste in Outlook 2013 from his Microsoft Exchange account to our smartermail server alias for all of our managers. Instead of doing a mailing list, we have lists set up by alias with multiple recipients as they are always static. 

When sending to one of these aliases, random users seem to get the email in plain text (all formatting on the copy and paste from excel is gone). 

We first thought it was a version issue between office products. However; when he sends to one of the users in the alias directly, the formatting is fully in tact and just fine. It is ONLY when sending to this user by sending to an alias that the user is part of. 

I thought it might have something to do with TNEF and MIME so i forced Exchange to send MIME only to smartermail and still the same issue is occurring. 

I don't think it is an exchange problem, because this is only when sending to a smartermail alias so I feel as though this has something to do with how Smartermail is receiving the email and distributing to all users in the alias. 

I would love to hear if anyone has any ideas?