Behind the Scenes: How Email Works
Email Header Definition
Email headers are an important part of every email message, indispensable to get it delivered. Find email header lines defined here.
LDAP Definition
LDAP lets email programs look up email addresses in white pages. Find LDAP (Lightweight Directory Access Protocol) defined here.
How Base64 Encoding Works
Find out how the clever technique of Base64 encoding makes it possible to send arbitrary data through email.
How HTML Email Return Receipts Work
HTML return receipts tell you when your mail has been opened. But how do such return receipts work, and do they always work?
Octet
An octet means eight bits and is used to specify the size of emails, for example.
How MIME Works
Find out how the Multipurpose Internet Mail Extensions (MIME) work to let you send attachments with your email messages.
APOP
APOP protects your user name and password when you check for mail.
How Uuencoding Works
Find out how Uuencoding makes it possible to send arbitrary binary data through plain text email.
POP Basics - How Your Email Program Gets the Mail
The Post Office Protocol is what enables your email program to fetch new mail. Find out more about its purpose and its scope.
POP Inside Out
Have you ever wondered what happens when your email client retrieves mail from a POP account? Here's how the Post Office Protocol lets you and your email software do it.
Subject
The "Subject" of an email message is a very brief summary of the message's contents.
SMTP Inside Out - How Internet Email Works
Have you ever wondered what happens when you click "Send"? Find out how SMTP, the Simple Mail Transfer Protocol, makes emails reach their destinations.
SMTP Diagnostics
SMTP Diagnostics sends a test message and prints all the conversation going on in the background to help you detect and troubleshoot email delivery problems. (Windows)
The Elements of an Email Address
Find out which characters are okay to use in your email address.
Are Email Addresses Case Sensitive?
Does it matter whether you type ReCipiENt@eXaMPle.cOm or recipient@example.com? Find out here, and learn what you should take to heart when creating a new email address.
Is the Length of Email Addresses Limited? If Yes, What is the Maximum?
Some email addresses are amazingly long and unwieldy. Is there really no limit to their length?
Unicode
Unicode assigns a number to each character no matter the writing system, language or operating system, allowing information to be exchanged without obstruction between computers.
The mbox Format
How email clients store mail locally and why ">From" is necessary sometimes.
Understanding SMTP Error Messages
Error 421 doesn't tell you much? Find out what the SMTP error message codes from mail servers mean.
What IMAP Can Do for You
Have you ever wished you could access your emails from multiple computers and locations easily and all your access points would always be in sync? This, and some more, is what an IMAP email account can do for you.