Secure email means providing end to end encryption to emails so that the communication between two parties through email is secure. End-to-end encryptions mean your data is transferred in an encrypted form that is difficult for hackers to decrypt and steal your information for misuse.
Various companies offer Secure Mail like:
  1. Protonmail
  2. Tutanota
  3. Mailfence
  4. Mailbox
  5. Thexyz
  6. Runbox
  7. Startmail


You should definitely read detailed reviews about Most Secure Email Providers before you go ahead and buy their services.