Electronic mail is older than the Internet, and the standards for Internet mail build on what happened before3.1. The main standard for Internet mail on which others are built, is the Simple Mail Transfer Protocol (SMTP ). Before this standard was implemented and available, electronic mail was transferred between systems using the file transfer protocol mentioned in the previous section -- an inefficient way of doing things.
SMTP was developed to support the transfer of mail across the Internet, and it is quite possible to send email ``in the raw'' by directly using SMTP. Sending email this way is either used by people who run email systems to diagnose problems, or by unscrupulous people who are faking email (i.e. trying to send email that looks as though it came from someone or somewhere other than where it really comes from). In addition to being possible to fake, email can also be easily intercepted, and read.
There are solutions to this problem of insecurity -- verifiable encrypted signatures for determining whether an email message is genuine3.2, and robust encryption of entire messages for keeping your email private3.3. If you have a real need to, you should investigate using encryption (PGP , or Pretty Good Privacy, is a good place to start), but it is far easier to remember to avoid trusting email too much.
Before the establishment of a standard for transferring ``multi-media''3.4 mail, email was limited to pure text -- and 7-bit ASCII text at that (in other words, pure US English text with no allowance for foreign language characters, including the ``£'' sign). The Internet standard for ``multi-media'' mail, is MIME , and was designed to be infinitely flexible -- so flexible that it is also used for indicating the kind of things being transferred across the World-Wide-Web.