This file comprises a great quantity of the medias types taken on the RFC2045
and RFC2046. This list is not exhaustive, you can add or decomment types.
The types are classified by category :

- text application
- multipart
- other applications
- images
- waves
- videos

To add a type, it is necessary to write to the following schema :

[extension_file] => '[type]/[subtype]';

Example, for an executable file (.exe)

exe => 'application/exe';

Last precision, made attention with the extensions in capital letters, R-MAIL
does not make the difference. It will thus be necessary for you to put the extensions
in small letters and capital.
