Spam

unwanted e-mail (usually of a commercial nature sent out in bulk)

Signature

text automatically appended at the bottom of an e-mail message

Packets

A packet is a chunk of digital information that includes data from a web page or email, and data that tells where it is going and how to put it together again when it arrives where it is going.

Mailing List

a list of names and addresses to which advertising material is mailed

Instant Messaging

 a form of real-time direct text-based communication between two or more people using shared clients.

email Address

An e-mail address identifies an email box to which e-mail messages may be delivered.

Electronic Mail

a computer-based form of sending and receiving messages via the Internet.