Management CSCU9B2 CSCU9B2 1

Email Management

Contents

•  Email clients – choosing and using •  Email message header and content •  Emailing to lists of people

•  In and out message management •  Mime attachments and HTML email •  SMTP, HTTP, POP, IMAP

•  Web mail

Email Client

•  The software that receives, displays, and allows the creation and sending of emails

–  What you use on your computer to read & write email

•  Lists messages,

–  usually has an address book for contacts, –  should offer folders for organising emails etc.

•  Some security support such as spam and scam detection

Choosing One

•  Open Source

– Eudora - www.eudora.com

– Thunderbird - www.mozilla.org/thunderbird

•  Proprietary

–  MS Outlook (probably most used) – Apple Mail.app (which I use)

•  There’s lots of others

MIME Protocol

•  Why is it needed?

–  The original mail system supported only ASCII text. –  For the history of email see

http://en.wikipedia.org/wiki/Email

•  MIME = Multipurpose Internet Mail Extension •  MIME allows:

–  Attachments to email messages

•  Not just ASCII characters

–  Alternative character sets –  Multi-part messages

•  Tells the email client how to handle the message content

–  What character sets to use

HTML Content

•  Early email clients displayed text and nothing more

•  MIME allows attachments and other character sets

–  Very important now!

•  HTML enabled email clients allow HTML to be used to design the display of an email

message’s content

•  Text that is obviously a URL is made into a link •  Email addresses link to compose a message

Writing HTML Content

•  Not everyone has a HTML enabled client, and some people turn it off, so you can’t be sure a HTML message will be readable

– E.g. some webmail clients like SquirrelMail – Also: some people simply turn HTML off

•  Because they prefer simple textual email

•  Because a great deal of the non-textual email is advertising

Email Headers

•  The message part of an email is its body •  Email messages also have a header,

which contains information about the message, the sender and the recipient •  Made up of Key:Value pairs

body

Email Header

•  From: email address of sender •  Date: date message was sent

•  Message-ID: automatically generated ID

•  In-Reply-To: ID of message being replied to •  To: email addresses

•  Subject: Subject of message

•  Cc, Bcc: other recipient addresses •  Content-Type: Usually a MIME type

Routing Info

•  The email header also tells you the route an email took between the sender and

recipient

•  Received: server name and IP address, mail server name

•  A message can have multiple received: lines

•  Read from bottom up to go from origin to destination

Received: from lek.cs.stir.ac.uk by yen.cs.stir.ac.uk (8.14.5) id qB3DSH9M019419; Mon, 3 Dec 2012 13:28:17 GMT

Received: from mail-pb0-f45.google.com by lek.cs.stir.ac.uk (8.14.5) with ESMTP id qB3DSFRb003986; Mon, 3 Dec 2012 13:28:16 GMT

Received: by mail-pb0-f45.google.com with SMTP id mc8so1918124pbc.32 for <[email protected]>; Mon, 03 Dec 2012 05:28:00 -0800 (PST)

MIME-Version: 1.0

Received: by 10.68.247.196 with SMTP id yg4mr29374650pbc. 167.1354541279724; Mon, 03 Dec 2012 05:27:59 -0800 (PST)

Received: by 10.68.56.74 with HTTP; Mon, 3 Dec 2012 05:27:59 -0800 (PST)

Date: Mon, 3 Dec 2012 13:27:59 +0000

Message-ID: <CAB4axPcAFcRK1xxFqYb7RUS933VCjUQ2xPLaNzwcwbAV [email protected]>

Subject: Example Email Header

From: Kevin Swingler <[email protected]> To: Kevin Swingler <[email protected]>

Faking/forging the Header

•  You can put what you want in most of the header,

–  You can pretend to be sending an email from somebody else, for example

•  You can add fake Received: lines too, but only at the bottom of the header

–  real ones are added by other servers once it has been sent

•  Unfortunately this is very easy to do.

•  Email is extremely insecure in all sorts of ways

Mail Architecture

Mail Servers

•  To send and receive email, you need access to two mail servers:

– Incoming – Outgoing

•  The outgoing mail server will be an SMTP server – Simple Mail Transfer Protocol

•  This handles moving email from the

sender to a mailbox for the recipient on the recipient’s incoming mail server

Incoming Mail Server

•  SMTP gets the mail from the sender to the recipient’s inbound mail server

•  There are a few options for getting the message from the inbound server to the mail client

•  Main two are:

– POP3: Post Office Protocol

POP3

•  Post Office Protocol

•  Used back when internet connections involved dialling in to a server

•  Allowed you to download all messages onto the client

•  Generally deleted them from the server •  Allows offline working on emails

IMAP

•  Internet Message Access Protocol

•  Mail client interacts directly with the server

– Messages stay on the server

– Headers downloaded before messages – Messages can be deleted without ever

downloading them (if the header suggests it) – Messages can be cached locally to allow

off-line working, but cache is synchronised with server

Web Mail

•  Hotmail, Googlemail (gmail), etc. are examples of web mail services

–  You interact with your mail through a website

•  Really a portal

•  Advantages are that you can gain access

from any computer – you don’t need an email client set up to read it

•  Disadvantages are that it can be slower and less flexible than a good email client

–  And you cant read old emails when you’re off-line

Spam Email

•  Unwanted email, either trying to sell you something or con you or …

•  Takes advantage of

– Email being free

– Email being insecure

•  Illegal in many countries, including the UK

– Ha bloody ha!

Spam Law, UK

•  The Privacy and Electronic

Communications Regulations 2003 •  It is illegal to send marketing email to

individuals unless:

–  you have their express consent

– you have a clear customer relationship

•  But the law isn’t working.

Spam Law, UK

•  If you do send such messages, they must:

– Reveal the identity of the sender

– Give a valid address for opt-out requests

•  Opt-out preferences must be respected •  You can also send messages if

– It is part of a sale negotiation

– It relates to similar products or services

Spam Protection

•  Spammers get email addresses from a variety of sources, including web pages •  If yours is on a web page, protect it to

make automated ‘harvesting’ impossible:

– Put it in an image, rather than using text

Un-Subscribing

•  A legitimate business must let you opt-out of receiving email

•  Should be by sending a short message (“op-out”, for example) to a specified address

•  Illegal spammers might treat this as proof that your email address is ‘live’ and sell it to others, so think before you opt-out

Spam Filter

•  They learn what your genuine email looks like and how it differs from spam

•  Take a little time to train yours by flagging spam messages as such

•  Most email clients have a facility for this

•  But spammers are very clever: don’t be taken in

–  If it looks to good to be true it almost certainly is! –  Be very careful in following links in emails

•  And remember that because it appears to come from (say) a bank, that means nothing at all

•  And never provide secret information (like passwords, pin numbers etc.) to a web form.