May 18, 2011, 11:40 p.m.
posted by juff
These days, e-mail is getting to be such a widespread practice that you may want to send things other than plain old, short text messages. For example, we e-mailed most of the chapters in this book as Microsoft Word documents to our long-suffering editor. Most mail programs now have commands for attaching files to e-mail messages, or at least including text files in messages.
If you want to send a text file by e-mail, just include the text file as part of your message. Note, however, that UNIX e-mail is designed for sending text, not for sending programs, graphics, or formatted word processing files. Luckily, several ways of cheating have been developed so that the e-mail system doesn’t realize that e-mail messages actually contain stuff other than text. MIME (Multipurpose Internet Mail Extensions) is the most widely used method. MIME is built into all current mail programs, so they handle it automatically. When you hear about e-mail with attachments, that generally means MIME. When we describe mail programs, we tell you whether they work with MIME.
Tip Before sending a file by using a MIME attachment, you may want to send a plain old, nonattached e-mail message to the intended recipient, asking whether he can handle MIME. Some mail systems reject, or discard, all e-mail with attachments. Because the e-mail worms and viruses everyone complains about are attachments, this is often a security policy. Good news! Your UNIX system is probably totally immune to most e-mail worms.