What a pain. It seems Android can’t open eml attachments by default. I’m using outlook for Android and it just throws a fit when I try to open the attachment.
Found a couple of eml readers in the Google store but they don’t seem to work with Outlook. Only solution so far is to forward the emails to my personal account (which uses the Google mail app) and this has no problems displaying the eml attachment.
If anyone has another solution then let me know.