Every device on the Internet has a unique IP address.

An outgoing mail server runs a Message Transfer Agent (MTA), or mail transport agent which routes message via SMTP. A Mail Delivery Agent (MDA) receives the message delivered by the MTA.

1. On a computer, an E-mail program is called a Mail User Agent (or E-mail client) e.g. Outlook, Eudora.
2. Before using an E-mail client, you must configure it (identify yourself, provide names of mail servers used by the ISP).
3. Browsers such as Navigator and IE come with browser E-mail programs built in.
4. Alternatively, use web-based E-mail (e.g. Hotmail), which use HTTP protocol (they are web pages!)
   • advantage: you can access it from any computer.
   • Disadvantage: you cannot access your messages unless you can find a WWW connection.

E-mail addresses take the form:

Multipurpose Internet Mail Extensions (MIME) – a protocol that extends SMTP to allow attachments.

• MIME identifies attached file by type and includes the type in the message header.
• This allows receiving mail system to load a player/program to run/view the attached file.
• Secure version of MIME is Secure MIME (SMIME)

Alternative to SMIME is Pretty Good Privacy (PGP), a publically available strong encryption program (“strong” encryption cannot be broken even by the most powerful computers).

Components of an E-mail: To (address) field, CC (carbon copy), BCC (blind carbon copy), Subject field, Attachment field, Message field, Signature field.

E-mail signatures: A few lines of unencrypted text identifying the sender automatically added to the end of each E-mail (typically name, company name, web address, phone number).

You can attach any type of file to an E-mail (displayed in E-mail clients using paper clip or similar).

E-mail servers may scan attachments and/or block them if they contain viruses or for security reasons.

Most E-mail clients allow you to store received (or even sent) E-mails in various folders. There is limited space available for storing files! Outlook stores E-mail on your hard disk.

Responding to E-mail:

• Reply – to the single sender of the E-mail.
• Reply to all – to the sender and anyone on the CC list (but not the BCC list)
• Forward – copies the E-mail to another person. A message passed from person to person becomes a thread.

Be careful:

• E-mail should be thought of as permanent, as a copy can always be kept. Be careful what you write!
• An employer has legal ownership of any mail sent during working hours or from a company machine.
• It is polite to respond with an acknowledgement of an E-mail fairly soon after receiving it.
• Consider also an “out-of-hours” message (“I shall be in my office from .... to ... on Monday” etc.)

Spam is junk E-mail e.g. penis enlargement adverts (they don’t work, by the way!), fraudulent financial offers etc.

• Spammers get lists of E-mail addresses from online directories, newsgroups etc.
• You can set up a spam filter so that your E-mail account blocks as much spam as it can detect based on the Subject line, the To/From fields and even the body of the message.
• A CAPTCHA test (Completely Automated Public Turing Test to Tell Computers and Humans Apart) is used to prevent automated spam systems from grabbing large numbers of E-mail addresses.

Personal Information Management (PIM)
A PIM program (e.g. Microsoft Outlook, Lotus Organiser, CorelCENTRAL, plus free online PIM software)

• schedules appointments and meetings (calendar function),
• stores contact information,
• manages tasks requiring groups of people.

Small hand-held PIM computers are Personal Digital Assistants (PDAs)

• Can use miniature keyboards or writing with a stylus
• Often contain software such as WP, Internet access, games etc.
• Can be interfaced with other computers to transfer data.

Wireless Application Protocol (WAP)

• Communication protocol between wireless/handheld devices.
• Provides text-based web access and secure E-mail facility.
• Uses a variety of HTML for web pages called Wireless Markup Language (WML)
• Advantage:
  • WAP provides access to the Internet etc. from anywhere without having to be plugged in.
• Disadvantages:
  • Small screens (difficult to read)
  • Low screen resolution – “conventional” web pages require much scrolling.
  • No attachments for E-mails.
  • Slow data transfer to/from other computers (often 14.4 kbaud)
  • Hacking into transmitted signal e.g. blue-jacking of the Bluetooth signal

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