Deeplink rendering / outlook settings

We have an application that generates deeplinks, but forcertain outlook users, the deeplink (hyperlink) comes across as plain text in the email. In virtually all other mail servers (lotus notes, gmail, etc it works fine). I have a hunch the issue is with the users outlook settings / spam filters. I followed the steps here to try to resolve the issue but was unsuccessful. Any help much appreciated. Here are the steps I tried to follow:
1 answers

It sounds similar to this issue:

Check to see what version of the deeplink module. Your one may not have the fix in for MS word in.

I know it's not MS word your having issues with but it could be down to a similar Microsoft security feature.