Entourage can encode attachments in any of the following formats. However, most users choose "AppleDouble" format for file attachments to ensure the recipient can properly open and access the file.

  • UUENCODE: This older method was developed originally for use with UNIX mail transfers. Most mail clients, including Entourage, are capable of encoding as UUENCODE.
  • MIME (Base64): The Multipart Internet Messaging Extension (MIME) method has emerged as the newer standard in all computer environments. The Base64 implementation successfully encodes a wide variety of files without increasing the size of the message stream.
  • AppleDouble: This method, developed by Apple Computer, Inc., is a packaging standard that allows files that are sent from a Macintosh computer to be received and opened in other computer environments and with other operating systems. If files that are packaged in this manner are sent using the Internet, they are encoded by one of the other methods.
  • BinHex: This is a combination packaging and encoding method for making files available to a Macintosh user. Although you can use this method to send attachments, the method is more commonly used to store files to be downloaded on non-Macintosh File Transfer Protocol (FTP) and web servers. The BinHex method increases the size of the attachment and, consequently, the size of the message to which it is attached.

Attaching files using an incorrect or incompatible encoding method can result in your email recipient receiving a corrupted attachment. When attaching a file to an email, you should change the preferences in Entourage so that attachments are set to be encoded using the "AppleDouble" encoding format.

To set the encoding options for an attachment:

  1. Create and address your email.
  2. Choose Attachments.
  3. Click Encode for any computer.
    • If the AppleDouble encoding option is not selected by default, select it.
    • The Append Windows Extensions to file names option adds the appropriate three character extensions to Microsoft Office files. If you are sending a Microsoft Office document to a Windows user, make sure you have selected this option. This option allows a Microsoft Windows user to open a Word file without manipulation.
  4. Press Return, and then send the email.