Email Server

When you've written that Very Important Email in your email client and hit "Send", a few things happen that you don't notice:

1. Your email client contacts your sending email server and hands off the email to it.
2. Your sending email server inspects the email to find the recipient email address.
3. The domain from the recipients email address is used to look up the recipients email server in DNS.
4. Your sending email server then contacts the recipients email server and hands off the email to it.
5. And hopefully at some point, the recipient opens her email client, which contacts her email server, which in turn hands off the email to it.