Email: Email allows you to send and receive text, HTML, images and other data files over the Internet. Email is one of the most popular online activities and has become a vital tool for electronic commerce.

Email Address: The Unique address within the Internet which allows people to send mail to you.

Email bounces: Email messages that fail to reach their intended destination. "Hard" bounces are caused by invalid email addresses, whereas "soft" bounces are due to temporary conditions, such as overloaded inboxes.

Email client: The software that recipients use to read email. Some email clients have better support for HTML email than others.

Email harvesting: The disreputable and often illegal practice of using an automated program to scan Web pages and collect email addresses for use by spammers.

Email header: The section of an email message that contains the sender's and recipient's email addresses as well as the routing information.

Email marketing: The use of email (or email lists) to plan and deliver permission-based marketing campaigns.

False positive: A legitimate email message that is mistakenly rejected or filtered by a spam filter.

Gateway: This is a hardware or software set-up that functions as a translator between two dissimilar protocols. A gateway can also be the term to describe any mechanism providing access to another system (e.g AOL might be called a gateway to the Internet).

Ham: Email that is generally desired and isn't considered spam.

Hard bounces: Email messages that cannot be delivered to the recipient because of a permanent error, such as an invalid or non-existing email address.

IMAP: Internet Message Access Protocol – A protocol used to retrieve email messages. Most email clients use either the IMAP or the POP protocol.

In-house list: A list of email addresses that a company has gathered through previous customer contacts, Web sign-ups or other permission-based methods. In-house lists typically generate higher conversion rates than rented lists.