Kenny,
See if this may be able to help:
In Windows Mail, click on Tools, Options, Security tab, dot "Internet Zone", uncheck "Do not allow attachments.....", uncheck "Block images and.....". Next, right click on that message and click on "Add Sender to Safe Sender List" (if you trust that sender) to help remove restrictions on email from that email address.
You might also check any program that you have installed since then may interact with Windows Mail, and disable any feature that does. For example a antivirus program that has an email scanning option.