The functions of Incoming Mail Server & Outgoing Mail Server
There are 2 types of server functions in email system: incoming and outgoing. It is worth a note that both functions can be performed by one single computer or two, and the choice is made by the email provider. The example below shows one single computer performing both incoming and outgoing functions:
1. Mary sent an email to Sam’s email inbox
2. Computer gave a command to Mary’s email system server
3. With SMTP, the outgoing server processed the email and sent it to the email system server where Sam’s email inbox located
4. The email system server, with SMTP, receive the email from Mary
5. Sam inquired the email system server if there are new emails
6. Incoming mail server used POP3 to precess the email and notify Sam of the new email
7. Sam viewed the email from Mary
Different types of incoming and outgoing mail servers
The functions of incoming and outgoing mail servers are actualized with the related TCP/IP protocols. Mail servers are decided depending on the choices of protocols, and the functions vary. The most common types for incoming mail servers are: POP3 servers – POP3 protocol; IMAP servers – IMAP protocol; HTTP servers – HTTP protocol. Outgoing servers normally use SMTP protocol, and that is why outgoing mail servers are called SMTP servers.
Why do we need to know the incoming and outgoing mail servers?
Take Outlook Express as an example. In order to set up an email account to send and receive emails on Outlook Express, you must know your incoming and outgoing mail servers.
From the toolbar, select Tool > Account > Add > Email > Your name > Email address > Email server (POP3, IMAP or HTTP) and then set up SMTP. You may inquire your email service provider for details.