Issue with Exclaimer and Outreach

Some of our users use a program called Outreach for mailing meeting invites. These users also have Exclaimer email templates applied to their accounts. We have an issue where parts of the meeting invites coming from Outreach get stripped if they also are on Exclaimer. When Exclaimer is turned off, the meeting invites from Outreach come through fine. I have attached examples of this. I am trying to find a solution so that these folks can keep using Outreach and Exclaimer together.