I emailed a Prism file from my Mac, but the recipient couldn't open it on his PC.

Prism makes identical files from the Mac and Windows version, so transferring files between platforms is usually straightforward.

The Windows version identifies Prism files as files that end in ".PZM" (ver 3) or ".PZF" (ver 4). If you use Mac OS 8 or 9 and frequently move files from Mac to Windows, go to Prism Mac's File&Printer Options (version 3) or Preferences (version 4) dialog, and check the option to end file names with ".PZM" or ".PZF" so they'll show up in the file list presented by Prism Windows. With Mac OS X, extensions are added automatically. When you use File Save, the saving sheet (dialog) has a "Hide extension" checkbox. Make sure it is unchecked.

You can also choose (at the bottom of the Prism Windows File Open dialog) to show all files, rather than only files that include the .PZM or .PZF extension.

Some Macintosh e-mail program encode attached files in a way that Windows e-mail applications can not decode. As a result, Prism for Windows can't open the file. It appears to be a Prism file, but is actually an encoded file. The Mac keeps track of which file should be opened or decoded by which application, but Windows does not see the codes for these file types. Windows only sees the extension that follows the file name.

When you email a Prism file from the Mac, set an appropriate encoding preference for e-mail attachments.

Microsoft Outlook Express 4.5

1. Choose Preferences from the Edit menu
2. Select "Message Composition" on the scroll list on the left side and set "Base64/MIME" for attachment encoding

Microsoft Outlook Express 5.0

1. Choose Preferences from the Edit menu
2. Select "Message Composition" tab
3. Click the button "Click here for attachment options"
4. In the opened window select "MIME/Base64"

If you use a different program, you'll probably find similar settings.