[alain94040]

I think you are overthinking this. If a user signed up and gave them your email for the purpose of trying your app, then that's the strongest indication that it's ok to email them.

Just don't be annoying. Don't send them daily updates with nothing interesting to say. Make sure they can always opt out. If you treat your (future) users with respect, everything will be fine.

[dwolfson20]

Thanks for the perspective. You're almost certainly correct that I am overthinking it.

[kris-jagasia]

have to agree with this. if a user signed up and you are sending them serious updates rather than marketing (and of course, if you honour their opt-outs) you're fine