When a Microsoft Exchange Server user sends a Simple Mail Transfer Protocol (SMTP) e-mail message with an attachment to a mail-enabled contact in the Global Address List, the mail-enabled contact may receive a Winmail.dat file attachment with the e-mail message instead of receiving the correct file attachment.
This issue may occur if the following conditions are true for the mail-enabled object on the Exchange computer:
- The default message format is set to Rich Text Format (RTF).
- The mAPIRecipient attribute is missing, is set to null, or is set to true.
Note This typically occurs if the mail-enabled contact is added by using a script.
To resolve this issue, change the settings in Active Directory Users and Computers so that the mail-enabled contact does not use RTF as the default message format. To do this, follow these steps:
- Open Active Directory Users and Computers. To do this, click Start, point to Programs, point to Administrative Tools, and then click Active Directory Users and Computers.
- Click the container where the mail-enabled contact is located.
- Right-click the mail-enabled contact in the right-pane, and then click Properties.
- Click the Exchange Advanced tab, and then click to clear the Use MAPI rich text format check box.
- Click Apply, and then click OK.