This page provides some information about encoding methods as used by e-mail client software.

Technically speaking encoding and encrypting are similar if not identical methods. The two terms coexist mainly because the scope of their usage is different. The process of applying a suitable code to an original message in order to change its form into one which is more advantageous for transmission, storage, reading, etc. In human communication, the process of translating mental imagery into linguistic expressions is characterized as encoding (a.k.a. translation) just as is the process, embodied in a microphone, of converting acoustical signals into electrical impulses. This conversion is done in such a way that reconversion into the original form is possible by decoding.

From a cryptographic standpoint it means the conversion of plaintext into "encoded" data by using a code which need not be secret, in contrast to encryption. In cryptography, the task of enciphering is one of encoding a readable message into a form that unauthorized receivers cannot easily decipher. In contrast to encrypted data encoded data should be well understandable by someone who knows well enough the code (e.g. morse code, ASCII code etc.).

 You can send E-Mail attachments with any of the following :

• The MIME (Multipurpose Internet Mail Extensions) standard uses Base64 encoding. It is the newest form of encoding and is a good choice for sending files to either Macintosh or Windows computers. It's the best choice in general and this is also why it's the default encoding selection in many email clients.
  
  On the Macintosh, there are two ways to send MIME attachments, AppleDouble and AppleSingle. (These are both Base64 MIME encoding, just different ways of doing it). If you want to use MIME, it's best to use AppleDouble when sending to Macintosh or PC users.
  
  AppleSingle is also good for Macintoshes but shouldn't be sent to PCs. An AppleSingle attachment may not be understood by a PC because it includes both the data fork and the resource fork of the file. The resource fork is useless to a PC.
  
  AppleDouble splits these files up during transport, so a PC can trash the resource fork when it receives it and just use the data fork. Since you often don't know what kind of computer your recipient has, AppleDouble is usually the best choice.
  
  However, since Base64 MIME encoding is a newer standard, some older mail programs don't support it -- so if your recipient has trouble reading your MIME attachments, one should try BinHex or Uuencode.
  
  

   Note: TROI also uses MIME as the default. As such you are encouraged to use it whenever possible in your communications with us.

• BinHex is a traditional Macintosh method for encoding of files. It is a good choice when sending Macintosh files to recipients who do not have a MIME compliant mail reader.



• Uuencode/Uudecode is best used only when the recipient asks for it. This will mainly occur when your recipient is using a UNIX or PC mailer that does not support . Since it's the oldest method, some newer email clients do not include support for Uuencode/Uudecode anymore.