How does Email works

Each Internet domain has email Server, when a user sends an Email…

1. Email client Program sends the message to Email server.
2. Email server contact to the Recipient’s Email server provided in the Email address.
3. Email server checks that user name is valid or not.
4. If found valid send email to the address’s email server.
5. When recipient log on his mail account, gets his Email.
   

Mailing protocols

Basically, a protocol represents standard method used at each end of a communication channel, in order to properly transmit information.

Generally four protocols are used to send and receive Emails:

Simple Mail Transfer Protocol (SMTP):
SMTP is used to deliver Email to the recipient mail server. Java mail Application communicates with company’s or user’s ISP (Internet service provider) SMTP server, that SMTP Server will transfer the message to recipient SMTP Server.

POP (Post Office Protocol 3):
This protocol defines a single mailbox for a single user and a standardized way for users to access mailboxes and download messages to their computers as well. This provides facility to users to retrieve e-mail when connected. Once the messages are downloaded from the server, you can disconnect the Internet connection and read your mail.

IMAP (Internet Message Access Protocol):
IMAP is a client/server most advanced protocol in which Email is received and held for user by his Internet server. It supports both connected and disconnected modes of operation, allows multiple clients to access the same mailbox and provides server side searches.

MAPI (Messaging Application Program Interface):
MAPI is used to send Email with in windows application and provide facility to take advantage of word processors, spreadsheets, and graphics applications. One of the most popular Email applications Eudora includes a MAPI Server.