In its simplest form, e-mail is an electronic message sent from one device to another. While many messages go from computer to computer, e-mail can also be sent and received by mobile phones, PDAs and other portable devices. With e-mail, you can send and receive personal and business-related messages with attachments, such as photos and documents. You can also send music, podcasts, video clips and software programs.
How E-mail WorksTo send e-mail, you need a connection to the Internet and access to a mail server that forwards your mail to its final destination. The standard protocol used for sending Internet e-mail is called SMTP, short for Simple Mail Transfer Protocol. It works in conjunction with POP--Post Office Protocol--servers. Almost all Internet service providers and all major online services offer at least one e-mail address with every account.
When you send an e-mail message, your computer routes it to an SMTP server. The server looks at the e-mail address (similar to the address on an envelope), then forwards it to the recipient's mail server, where it's stored until the addressee retrieves it. You can send e-mail anywhere in the world to anyone who has an e-mail address. In fact astronauts on the international space station use e-mail to keep in touch with their earth-bound colleagues.
At one time, you could only send text messages without attachments via the Internet. With the advent of MIME, which stands for Multipurpose Internet Mail Extension, and other types of encoding schemes, such as UUencode, you can now send formatted documents, photos, audio and video files. Just make sure that the person to whom you send the attachment has the software capable of opening it.