To send an email that no one but me and the recipient can read
There are several options for sending a confidential email that no one but the sender and recipient/s can read. Unlike traditional letters, email isn’t protected by an envelope and isn’t just one copy of a message travelling from the sender to the receiver. Rather, it is plainly visible to anyone who has access to its several copies, which are stored in several computers along the way. So you have to trust that those copies won’t be read by your email provider, the Internet service provider and anyone else responsible for sending and delivering your message. If you want to be sure that no one but you and the recipient can read your messages, the solution relies on using encryption. The Electronic Frontier Foundation has a good introductory guide to communicating with others in a secure way.