Introduction to SMTP

Internet email uses a protocol called Simple Mail Transfer Protocol (SMTP), which is an IETF standard. Much like HTTP, it is a simple text protocol over TCP, using port 25 by default. In this section, we will look at a small example of using lettre for sending emails. For this to work, let us set up our project first:

$ cargo new --bin lettre-example

Now, our Cargo.toml file should look like this:

$ cat Cargo.toml
[package]
name = "lettre-example"
version = "0.1.0"
authors = ["Foo<[e-mail]>"]

[dependencies]
lettre = "0.7"
uuid = "0.5.1"
native-tls = "0.1.4"

Let's say we want to send crash reports for a server automatically. For this to work, we need to have an SMTP server running somewhere accessible. We also need to have a user who can authenticate using a password set up on that server. Having...