Platform: WLM 2012 on Win7 Pro

My employer sends scheduling emails with ICS files, but when I view these emails using WLM, those files show with names like ATT00095.TXT. If I view these same emails on my Android phone or Kindle tablet, the attachments show as ICS files. I know the purpose of these files, but why the difference in the way they show up? Is it because Windows doesn't know what to do with them?

For these emails, I'm using an account with my ISP, not a Hotmail or Google account.