Behind the Scenes: How Email Works
APOP protects your user name and password when you check for mail.
Are Email Addresses Case Sensitive?
Does it matter whether you type ReCipiENt@eXaMPle.cOm or firstname.lastname@example.org? Find out here, and learn what you should take to heart when creating a new email address.
Email Header Definition
Email headers are an important part of every email message, indispensable to get it delivered. Find email header lines defined here.
A carbon copy (Cc) lets you copy additional recipients on a message. Their names and addresses will be visible to all recipients but distinct from direct (To) recipients.
Curious what email programs mean when they ask for a "From:" address or name? Learn about the "From:" header and what it should contain in the email glossary.
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?
How MIME Works
Find out how the Multipurpose Internet Mail Extensions (MIME) work to let you send attachments with your email messages.
Is the Length of an Email Address Limited? If Yes, What is the Maximum?
Some email addresses are amazingly long and unwieldy. Is there really no limit to their length?
How Uuencoding Works
Find out how Uuencoding makes it possible to send arbitrary binary data through plain text email.
LDAP lets email programs look up email addresses in white pages. Find LDAP (Lightweight Directory Access Protocol) defined here.
An octet means eight bits and is used to specify the size of emails, for example.
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.
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)
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.
The Elements of an Email Address
Find out which characters are okay to use in your email address.
The "Subject" of an email message is a very brief summary of the message's contents.
The mbox Format
How email clients store mail locally and why ">From" is necessary sometimes.
Wish to know what the "To:" field is for, and whether you need to enter anything at all? Find out in the email glossary.
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.
Understanding SMTP Error Messages
Error 421 doesn't tell you much? Find out what the SMTP error message codes from mail servers mean.
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.
What Is the Default IMAP Port?
Are you setting up an email account in your email program using IMAP and need to specify a "port" number? Here are the ports used by default for IMAP access (with and without encryption).
What is the Default SMTP Port?
Setting up your email account in an email program and need to specify the "port" for the "SMTP" server? Find the ports used by default (and set down more or less strictly as standards) by SMTP, and the port numbers most promising to try.
What Is the Default POP Port?
Your email program or service asks for a POP "port number" when you try to set up downloading mail? It even suggests something, which, though, seems not to work? Find the standard POP email ports to trywith and without transport em security enabled.