PC Win DOS: How the WINMAIL.DAT File Effects Attachments

• Microsoft Mail for Windows, versions 3.0, 3.2, and 3.2a

SYMPTOMS

When Microsoft Mail for Windows sends a message with attachments, it dumps some raw data into the message body. When another Windows client receives this mail message, it parses and removes the raw data so the user never sees it.

A problem arises when the mail message is read by different clients. For example, the MS-DOS client or a foreign mail system client does not have the ability to remove the raw data. As a result, the unreadable data is left in the message body.

CAUSE

The "invisible attachment," or WINMAIL.DAT file, should remove the raw data in the attachment's message body.

RESOLUTION

The MS-DOS client was changed in version 3.0b to provide the following functionality for mail sent from the Windows client:

1. The MS-DOS client shows a text list of the file attachments in the header of the message file. This list corresponds to what a user would see in the Attachments, View or Save.

2. The WINMAIL.DAT file no longer shows up as text in the MS-DOS client. Foreign mail clients may, however, still see the raw text. The MS-DOS client user can still see the text from the View or Save menus of the MS-DOS client.