Redmine

We use redmine for a few things, but one of the principal ones is running our internal helpdesk. Our users never see redmine directly -- they email helpdesk@example.com and the email is read into redmine and a ticket is created. Once we made the decision to plain-text everything this has been working nearly flawlessly for three years and multiple versions of redmine.

A few weeks ago we noticed that there were more and more html entities -- principally non-break spaces -- are creeping into the issues that were posted via email. Not a show-stopper but a bit annoying. An example would be:

I am getting email alerts about voicemails on my desk phone, but when I try to find/play them on the desk phone, they’re not there. 

 
I have to play them through the e-mail link.
 
 
 
Some User

With no smoking gun, and since we were overdue, we upgraded to redmine from 2.2.2 to 2.3.2 in hopes this would fix things. Unfortunately, the only thing this has done is made the problem a bit worse. I've done quite a bit of searching and it seems I'm alone here or my google fu is failing me.

Redmine / Email Details:

• Emails are coming from Exchange 2010 via IMAP. Most are coming from Outlook 2010 for PC with a few via webmail or Outlook 2011 for Mac.
• Redmine 2.3.2 is running on Ubuntu 12.04 on rails 1.8.7 / nginx 1.2.3 / passenger 3.0.17; backing data store is mysql.

I'm happy to provide more details if it helps the cause.