Email

1
E-mail listsclient view

• Volin Karagiozov
• University of Mining and Geology
• St. Ivan Rilski Sofia
• volin_at_mgu.bg

2
Everybody has used e-mail!

• But how many have read documents, which set the
  standards for e-mail?
• These standards have been set up in the
  documents
• RFC 822 / RFC 821
• MIME standards set in
• RFC 2045/2046/2047/2048
• (old version RFC 1521/1522)

3
Mail Standard RFC822

• Published in 1982
• Lines no longer than 1000 char
• Message body - plain US-ASCII text
• Message header lines - plain US-ASCII text
• Limit on message length

4
RFC 822 restrictions

• no multiple objects in a single message
• no multi-part message bodies
• no non-textual bodies
• no X.400 messages can be gatewayd
• no multifont messages

5
ASCII times are over!

• Now we want
• National language support
• Possibility to send
• pictures
• audio files
• other applications
• video files
• multimedia applications

6
MIME - Multipurpose Internet Mail Extension

• RFC 2045-2048 obsolete RFC 1521, 1522,1590
• RFC 2045 Format of Internet Message Bodies
• RFC 2046 Media Types
• RFC 2047 Message Header Extension for
  Non-ASCII Text
• RFC 2048 Registration Procedures
• To solve RFC822 restrictions without serious
  incompatibilities with it

7
MIME defines new header lines

• MIME-Version header field
• MIME-Version 1.0
• The content type header field to specify the the
  type and subtype of data in the body
• Content-Type Text/Plain CharsetISO-8859-1
• Content-Transfer-Encoding field to show how data
  is encoded
• Content-Transfer-Encoding QUOTED-PRINTABLE
• Content-ID and Content-Description for future use

8
Content type possible values

• Text - textual information
• Image - for transmitting images (gif,jpeg)
• Audio - requires audio output device
• Video - to display moving images, like mpeg
• Application - information to be processed by
  application program
• Multipart - to represent compound, possibly
  embedded parts
• Message - an encapsulated message

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Content-transfer-Encoding

• base64 - every 3 bytes are represented with 4
  7-bit ASCII characters
• quoted-printable - will code only non-ASCII
  characters in the text, 76char lines
• 7bit - no coding, already 7bit
• 8bit - have to be transported as 8-bit
• binary - as 8bit, but may contain long lines

10
Quoted-printable

• Suitable to present most European languages which
  are based on ISO 8859-x standard
• Non-ASCII chars will be coded with 3 chars
  followed by code in base (16) Examples
• Ü DC ä E4 ö F6

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Where to get more info about MIME

• RFC archive with all RFC-s in plain text
• ftp//ftp.ripe.net/rfc
• Mark Grands MIME Overview
• http//www.mindspring.com/mgrand/mime.html
• comp.mail.mime FAQ
• http//www.cis.ohio-state.edu/text/faq/
  usent/mail/mime-faq/

12
How e-mail works

• Mail User Agent (MUA) - program, with which human
  users read, create and manage e-mail
• Mail Transport Agent (MTA) - handling the
  movement of messages among computers,
  non-real-time manner SMTP - Simple Mail Transfer
  Protocol - must be installed at every Internet
  Host

13
Working protocols

• SMTP - primary mechanism for moving mail around
  TCP/IP network, handles sites with permanent
  connections
• SMTP delivers mail, not allows user to collect it
  - sometimes the latter is more convenient
• POP, IMAP - fill the gap, they are oriented to
  serve users when they want

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POP, IMAP

• Aim - to build a distributed e-mail
  infrastructure
• LAN oriented, vendor specific
• POP - Post Office Protocol, latest version POP3,
  RFC 1725 (1460)
• IMAP - the Internet Message Access Protocol,
  latest version IMAP4, RFC2060 (1731)

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What we want from Mail client?

• Good user interface
• advanced text editing
• spelling checker
• attachments allowed
• addressbook (with groups!)
• MIME
• uudencode/decode

• Encryption!
• mailing lists
• pager support
• multiple accounts
• multilingual support
• full text indexing search
• message filtering
• and more

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more requirements for mail client

• signatures (multiple?)
• database
• sophisticated send
• send e-mail to all my students who live in
  Liberty street
• download headers and delete mail from server
  based on header info

• UseNet Newsgroups
• Live spelling
• Thesaurus
• auto-dialing
• Free Internet Fax
• Confirmation ability

17
Mail Clients

• You can find 28 mail clients in Tucows ultimate
  software collection for Win95, 13 for Mac and 11
  for win 3.x
• They need from 65K to 4.5M memory
• Tucows has mirrors in many countries
• one in Croatia
• http//www.tucows.sk

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Most popular clients

• The Pegasus Mail, no fee, version 3.01b
• http//www.pegasus.usa.com/
• FAQ http//www.let.nl/pegasus/faq.html
• Eudora (Qualcomm Inc.)
• Eudora Pro 4.0.2 (v. 4.1 beta testing)
• Eudora Light 3.0.5
• http//www.qualcomm.com/

19
Problems going from Eudora to Pegasus

• Your Adressbooks are not convertible.
• There exists Interguru Web-site to help you to
  convert Eudora nickname file to Pegasus address
  file
• http//www.interguru.com/eudopega.htm

20
To compare Mail Clients

• Strouds Mail Client Reviews with about 20
  packages reviewed
• http//cws.internet.com/32mail-reviews.html
• Interview Internet Client reviews
• http//www.eqp.com/egrinter.html
• Tucows has evaluated all packages with 0.5 - 5
  cows.

21
Some words about Netiquette

• Be polite!
• Cite as small part of the letter as possible!
• DO NOT USE UPPER CASE LETTERS THROUGHOUT THE
  LETTER
• Use smilies -) -( -)
• Take differences in the culture into account.

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Questions

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