Last updated: 99.05.11

Background

This document is available on the Internet at: http://www.barefeetware.com/email/imap/.

It was presented as a slide show at a Club Mac meeting in Sydney on 9 December 1998

The presentation is intended introduce some of the new email possibilities, especially with the wider adoption of the IMAP standard.

Presenter: Tom Brodhurst-Hill, Managing Director.

Email Communication
Email communication involves sending and receiving.

On the Internet this is done by:
    1. SMTP for sending.
    2. POP for receiving.



Protocol
SMTP = Simple Mail Transfer Protocol
POP = Post Office Protocol


Basically, they are just text transactions, with meaning such as:
    1. I am about to send a message.
    2. OK, go ahead.
    3. Here is the recipient address.
    4. OK, got it.


You can actually get in at the low level communication via a telnet session.


Ports
Each server protocol can operate on its own port number. Everyone usually uses the same port number for a particular service, eg:
    1. 80 for Web
    2. 25 for SMTP
    3. 110 for POP
    4. 143 for IMAP


Because SMTP and POP have different port numbers, the POP and SMTP servers can actually be run on the same computer, answering requests independently.

Limits of POP
POP is very limited as a method of receiving email.


It can basically only:
    1. Get a list of waiting email.
    2. Download those messages to the local hard disk.
    3. Delete them from the server.


Some basic limits of POP are:
    1. When you move from one workstation to another, your existing email is left behind.
    2. There is no way to share email between users of the same work group.
    3. Does not allow management of mailboxes stored on the email server.

Proprietary Alternatives
For a business with a few users, or a few thousand users, POP is not enough.


Businesses often choose a proprietary email system such as MS Mail, MS Exchange, Netscape server, QuickMail or Communigate.


However, these proprietary systems come at a cost:
    1. Usually only one type of email client software can be used.
    2. Communication with the outside world (eg the Internet) is very difficult.
    3. Upgrades often require a transition period, retraining and a lot of down time.


IMAP to the Rescue
IMAP provides the best of both worlds:
    1. Uses established Internet standards.
    2. Provides the features required for collaboration, such as server storage.


It provides functionality such as:
    1. Messages are stored on the server.
    2. Off line copies of messages can be stored and synchronised with the server.
    3. As well as the INBOX, other mailboxes and directory structure can be maintained.
    4. Users can move from one workstation to another and still see all their email and mailbox structure.
    5. Several people in a work group can each access a shared account, and others can see immediate action.
    6. Drafts of outgoing messages can be stored on the server.
    7. Access privileges can be set for each user of a shared mailbox.
    8. Each message can have various flags set.

Software
Although IMAP is a long established standard, software support, especially for the Mac OS, has only escalated fairly recently.

BareFeetWare has been comparing various available options.

Email Client Software
An in depth and ongoing comparison of various Mac email clients appears at:
http://www.barefeetware.com/email/clients/

They include: Netscape Communicator, Outlook Express, Mulberry, Mailstrom, PowerMail, Simeon.


Demonstration
Time and technology permitting, a demonstration of an email client and server package will follow.

    1. AppleShare IP 6.1
    2. Mulberry 1.4


      Contact
      Please don't hesitate to contact us if you have any questions.


      Return to Parent Folder