Nadia is concerned about the content of her emails to her friend Danielle being read as they move between servers. What technology can she use to encrypt her emails, and whose key should she use to encrypt the message?

Nadia should use Secure/Multipurpose Internet Mail Extensions (S/MIME), which supports asymmetric encryption, and should then use Danielle’s public key to encrypt the email so that only Danielle can decrypt the messages and read them. Secure POP3 would protect messages while they’re being downloaded but would not protect the content of the messages between servers.