PGP-encrypted emails? It becomes a question of security vs convenience eventually with security considerations (Someone mentioned dating sites are more engagement > security).
There is no 'safest' way with encryption. It's a matter of time before it's breached.
For example, Canonical's Launchpad requires you to sign "code of conduct" with your GPG key before doing certain actions. And, if I remember correctly, they do send GPG encrypted emails for key ownership verification.
There is no 'safest' way with encryption. It's a matter of time before it's breached.