The above are the basic building blocks of an email message. However, as with snail mail letters, you might want to include attachments to your message. These attachments are usually files on your system that you might want to include with your message. These files can be text files, program files, picture files, or sound files - in fact any type of file that your system and the recipient's system can handle. With this type of attachment you assign the file you wish to attach to a specific type and subtype.
Text is used for normal text type documents.
Normally you do not have to worry about this type since it is generated automatically when you specify attachments. Native word processing files should also use this type. If you use these types your email program will be able to interpret the files correctly and display them as appropriate. That's because multiview uses datatypes that can automatically detect what sort of file is being displayed. You do need to have the datatype for that file type in your datatype directory, however.