To protect your computer, Microsoft Outlook does not allow you to receive files of certain types (such as .exe files) as attachments, because of their potential for introducing a virus into your computer. These files are blocked by Outlook by default. If Microsoft Exchange is used in your organization, only the e-mail server administrator can unblock these file types. These file types cannot be unblocked by end users of Outlook.

The following file types are blocked by default in Outlook:

These are just few of the file types blocked by Outlook. There are many other file types. For more information, visit: Blocked attachments in Outlook.