You need to provide content, regardless of how you communicate. If your means does not allow reproduction of content, then it is very secondary (yes we chat a lot but can't prove what you chat about....again your word alone is not good enough).
Everyone needs to convince a total stranger, the Embassy CO, that you have a legitimate relationship. Your word alone is not good enough. So content is key. They need to read about what you talk about so they can determine legitimacy.
Some people don't use emails. With all the technology who really use their emails. Me personally we use everything but emails. Emails are for exchanging the private paperwork. ..I have to many apps to use yahoo and gmail....