How to send a more than one attached files.
(How to create compression settings)

For Windows

1. Right-click the file or folder you want to compress and select [Send]-[Compressed (zip format) folder].
2. Put the desired multiple files in the created compressed folder.
3. Specify this compressed folder as an attachment.

For Mac OS X

1. Start Finder.
2. Select the folder or file you want to compress.
3. Select Create Archive from the Finder's File menu.
4. Specify the created zip file as an attachment.