Is it safe for email or message apps (OTR or XXMP)?

I am looking for a contact method that employs good encryption. Email is mainly PGP encryption, but PGP can not always change the algorithm. Signal that uses OTR needs to have a phone number. There is also Chat Secure that uses XMPP, but I have doubts that it uses secure encryption. Which method is the most secure and secure?

2 posts were merged into an existing topic: What is a safer encryption than PGP by email?