Terminology

DKIM

DomainKeys Identified Mail: a system for digitally signing email that provides the means to securely verify that the email's origin is legitimate.

DNS

wikipedia:Domain Name System: a naming system for computers, services, or any resource connected to the Internet or a private network (i.e. that identifies "google.com" with its internet protocol address)

FQDN

wikipedia:Fully qualified domain name: a domain name that specifies its exact location in the tree hierarchy of the Domain Name System (DNS).

MTA

wikipedia:Message transfer agent: an email relay service, i.e. Postfix, QMail or Exim4.

SMTP

wikipedia:Simple Mail Transfer Protocol: a network protocol for sending email to a remote server, often involving password authentication and end-to-end SSL encryption.

SSL

(a.k.a Transport Layer Security) a method of connecting to a remote network host that encrypts traffic on any given network protocol that uses it.

TLS

wikipedia:Transport Layer Security a method of connecting to a remote network host that encrypts traffic on any given network protocol that uses it.

cron

wikipedia:Cron: a job scheduler for UNIX-like operating systems

installation directory

The directory (folder) on the web server where X2Engine is installed. You will know that you are operating within this directory when you see a file constants.php and the following subdirectories: assets, css, custom, framework, images, js, protected, themes and uploads.

URI

wikipedia:Uniform Resource Identifier: The part of a URL that identifies the resource on the server to be accessed. In the context of the API, this refers to the relative path within the web server based in the web root of X2Engine, i.e. index.php/api2/Contacts/324.json as opposed to the full URL, which begins with the protocol (i.e. "http") and might also begin with a path relative to the web site's document root

user menu

The menu accessed by clicking on one's own username in the far upper-right-hand corner of the application.