Not sure what IT support means by IMAP server? Wondering what exactly a "From" header is in an email?

This concise glossary lists the most common email terms and their meanings.

APOP, short for Authenticated Post Office Protocol, is an extension of the Post Office Protocol that allows passwords to be sent in encrypted form. APOP is more secure than regular plaintext POP authentication, but it also has serious shortcomings.

An attachment is a file (such as an image, a word processing document, or an MP3 file) that is sent with an email message.