Outlook Contacts Addressable by FaceTime and iMessage
The simplest way would be to make the contacts from Outlook into a clickable option on Internet Accounts > Hotmail/Exchange accounts. For instance, in Settings > Internet Accounts, a Gmail account has Mail/Contacts/Calendars/Notes as clickable options. If a Gmail user clicks the contacts box, then their Gmail contacts show up in Apple's Contacts app, and their Gmail contacts can be used with FaceTime and iMessage. However, my Hotmail account only has Mail/Notes as options. Please add contacts to the list of possible account integrations. This will open up FaceTime and iMessage. Yeah, yeah, I use Skype, I know. Try getting my 68 year old mother to use Skype.