Here is a list of the Acronyms and Jargon you will commonly find in discussions of email systems.

AJAX
Asynchronous JavaScript And XML. A newer technology for increasing the speed and usability of the web by allowing updating of web page information continuously. It is being used to improve the software being used to access email over the web (webmail).

Attachment
If you want to send some other computer document to someone with email then you “attach” the document to the mail. There is a standard protocol for doing this – MIME – which can encode any file – documents, spreadsheets, pictures etc provided the type is registered with IANA (Internet Assigned Names Authority).

Client
Program that runs on the users PC – mail client is the program you use for your email. Examples include Eudora, Microsoft Outlook Express etc

DNS
Domain name server – computers on the Internet that provide the look up function allowing names rather than numbers to be used to identify and contact other computers.

Domain
Part of your email address (the bit after the @ sign) but also part of the system that the Internet uses to refer to computers connected to the Internet rather just by numbers (known as IP addresses). It is a hierarchical distributed system with each level divided by full stops (periods). There is a top level domain such as .com or country codes such as .uk and then further levels to create the actual domain.  Domain registrars are the organisations that administer domains and provide the information to the Internet. So the .com domain is administered by companies such as Network Solutions but once you have registered a domain if you also run a DNS server then you can create sublevels. So you could in principle register nearlyallaboutemail.com with Network Solutions and then create other levels such as almostnearlyallaboutemail.com. Computers on the network each have a name such as mail.simplymailsolutions.com (a mail server) or www.simplymailsolutions.com (a web server). Multiple names can be created all pointing at a single server which is how shared web hosting is set up.  In the UK the domain register is Nominet and which administers the .co.uk, .org.uk and .net.uk domains (but not for example .ac.uk the academic addresses used by Universities and colleges).

ISPs normally offer email addresses that are part of their domain – eg jim.bloggs@anispsomewhere.co.uk or sometimes jim@bloggs.anispsomewhere.co.uk and charge extra to use it with your own domain – eg jim.bloggs@bloggsmotors.com. The costs of domains have fallen particularly .co.uk domains. The advantage of getting a domain (apart from the personalisation you get for your organisation) is that it is transferable from ISP to ISP and to companies who specialise in providing mail hosting.

EPP
Extensible Provisioning Protocol  is a new way of registering and maintaining domain names. The UK registrar has an FAQ: http://www.nic.uk/tag/epp/faq/

Email address
An Internet email address consists of two parts separated by the @ sign – the username before the @sign and the domain after the @ sign. A number of other forms of email address have existed in the past with systems such as MCI mail and Compuserve but have all really been superseded.

IMAP
Internet Message Access Protocol. This protocol was developed to make access to mail from more than one computer much more feasible compared with POP3.
Link:     http://www.imap.org/

IETF
Internet Engineering Task Force. The guys that are responsible for the technical side of the Internet.
Link:     http://www.ietf.org/

IANA
Internet Assigned Names Authority. Responsible for providing a lot of the critical information used by the Internet to function correctly.
Link:     http://www.iana.org/

LDAP
Lightweight Directory Access Protocol. Thisis an Internet protocol that email and other programs use to look up information from a server and is aimed at solving problems associated with larger number of mailboxes and other services run for larger numbers of users.
Links:   http://ldapman.org/
http://www.openldap.org/

ISP
Internet Service Providers. The guys that have built and give access to the Internet!

Mailbox
The bit of the mailserver that stores your email.

MIME
Multipurpose Internet Mail Extensions. The standard for attachments which have to be registered with IANA.
Link:  http://www.iana.org/assignments/media-types/

PIE
Provider Independent Email — most ISPs provide a free email address but you have to change if you change provider. If you use your own domain for your email then the address does not change when you change ISP. So PIE just means getting your own domain. Of course it also means that you can get your email service with extra features from a Email Service Provider.

POP3
Post Office Protocol 3 is the standard commonly used to get email from the server (POP Server).

POP Server
The computer that stores your mail. It could in fact be a single computer or a whole bunch of them depending on how many mailboxes there are on the server. You will need an account on a server to access your mailbox usually with just a password and the name of the mailbox.

RFC
The documents that specify the technical aspects of the Internet.
Link: http://www.ietf.org/rfc.html

Server
A computer connected to the Internet that provides services to users. Hence mailserver computer that provides email. This site has more details of server programs such as sendmail, MS Express etc

SMTP
Simple Mail Transport Protocol. Protocols are the rules the Internet uses to make sure that all computers on the net can work together. They are developed in a collaborative process by the Internet Engineering Task Force and published as RFCs (Request For Comments).

Webmail
Nowadays most mail servers allow users to access their mail over the Internet via a web browser and this is known as Webmail. The functionality varies greatly and also depends on the capabilities of the mailserver and how it is set up. For example with servers such as Microsoft Exchange email is retained on the server even though you download to your pc when in the office or at home. This means that when you access via webmail  (known as OWA or Outlook Web Access) you have access to your complete inbox and outbox and can even access attachments connected with the mail messages.