Mail service lets network users send and receive mail over your network or across the Internet.
Mail service sends and receives mail using the following standard Internet mail protocols:
Simple Mail Transfer Protocol (SMTP)
Internet Message Access Protocol (IMAP)
Post Office Protocol (POP)
A standard mail client setup uses SMTP to send outgoing mail and POP and IMAP to receive incoming mail. Mail service includes an SMTP service and a combined POP and IMAP service.
Mail service also uses a Domain Name System (DNS) service to determine the destination IP address of outgoing mail.
The following figure gives an overview of how the components of Mail service interact: