E-mail

 E-mail system components

X.400 Components

• X.400 defines a whole range of protocols for transferring mail between e-mail servers.
• The Three main components are:
• UA=> user agents
• MTA => Message Transfer Agent
• MTS => Message Transfer System
• E-mail Client (UA, User Agent) responsible for all user interaction such as
• reading and composing messages. It runs on the
• MTA (Message Transfer Agent) responsible for transferring messages from
• one user's mailbox to another or to other MTAs for delivery.
• MTS
• Responsible for  transferring messages of all types for the UA that creates the message to the destination UA
• Directory services Personal Address Book, Global Address List.

X.500

• is a set of directory services developed to help users in distributed networks locate users on other networks to whom they want to send messages

• Post Office (Information store, Message store) location of all user messages.

E-mail protocols
Transport/Delivery protocols

• POP3 (Post Office Protocol) and IMAP4 (Internet Mail Access Protocol)
• describes how e-mail client interact with email server.
• SMTP (Simple Mail Transport Protocol)
• describes how e-mail servers transfer email message to their intended recipients.
• SMTP works with other e-mail programs to provide both a client and a server the function to send and receive e-mail messages.
• used on the Internet, UNIX and in the TCP/IP stack
• MIME (Multipurpose Internet Mail Extension)
• defines the method in which files are attached to SMTP messages.
• MHS (Message Handling Service) within NetWare
• similar to X.400 => one computer on the network is the MHS sever and it translates messages between computers that may be using different e-mail systems

Directory Services

• LDAP (Lightweight Directory Access Protocol)
• X.500 (see above)

Messaging APIs

• MAPI (Message Application Programming Interface)
• MS standard and incorporated throughout all of its office products.
• VIM (Vendor-Independent Messaging) from Lotus
• Scheduling

Groupware

• eg. BBS, Internet news, Interactive conferences, MS Exchange, Lotus Notes.
• Group discussions
• Workflow automation.
• Help Desk
• Collective document creation.
• Internal publishing