174. Email Marketing › key terms and concepts An email authentication system designed to verify the DNS domain of anDomainKeys email sender and the message integrity. The act of getting subscribers to confirm their initial subscription via aDouble opt-in follow up email asking them to validate their address and hence opt-in again. The failed delivery of email communication due to an undeviating reasonHard bounce like a non-existent address. An email database a company generates itself without purchasing orHouse list renting names. Certain HTML “tags” are used to structure the information and featuresHyperText Markup within a web page. As an example, HTML emails usually containLanguage (HTML) graphics and can be interactive.Internet Protocol (IP) The IP address is an exclusive number, which is used to represent everyAddress single computer in a network.Internet Service This is the company providing you access to the Internet e.g. MWEB,Provider (ISP) AOL, Yahoo! etc). The percent of emails determined as opened out of the total number ofOpen rate emails sent.Opt-in To give permission for emails to be sent to you. Also known as unsubscribe - The act of removing oneself from a list orOpt-out lists so that specified information is no longer received via email. A method used by major ISPs to confirm that emails do originate fromSender ID the domain from which it claims to have been sent.Simple Mail Transfer SMTP is a protocol for sending messages from one server to another.Protocol (SMTP) The failed delivery of an email due to a deviating reason like anSoft bounce overloaded mail box or a server failure.Spam Email sent to someone who has not requested to receive it - EVIL!Sender policy Sender policy framework is an extension of SMTP that stops emailframework (SPF) spammers from forging the “From” fields in an email. Text emails or plain text emails do not contain graphics or any kind ofText markup. This refers to the number of individuals who forwarded a specific emailUnique forwarders on. A list of accepted email addresses that an ISP, a subscriber or otherWhite list email service provider allows to deliver messages regardless of spam filter settings. 171