Please note that as of this writing, NetBITS is on hiatus. Many of you have asked about how to attach files to email so that the recipient receives them reliably. There are dozens of possible combinations of email clients, attachment methods, and encoding systems. As far as we've seen, it's always a matter of experimentation to get the right mix in any given situation. The root of the problem is how email itself is sent.
Email is just a stream of data with a recipient and certain standard headers on the front.
There are also differences in which encoding formats are supported by different mail clients. You'd think there would be at least one standard in common, but that's still to come. If you wanted to include a file in email going over the Internet or between different mail systems or services, you would encode it and then paste it into the body of a mail message. Many older mail programs limited message size, which resulted in some amazing attempts to send large files in multiple pieces and reassemble them on the other side. Encoding a file was necessary only for binary data, which, as you might recall from previous issues of NetBITS, is data that includes bytes which aren't pure text.