Outlook is blocking most file types in attachments

[linda]

Outlook appears to have blocked many file types that are
received as attachments by assigning a Level 1 to them.
Does anyone know how I could change some of the
assignments from Level 1 to be unblocked or to be a Level
2 so that I can receive them? So far, the only thing I
can find is that Microsoft Exchange Server allows it, but
I do not use that product.

Thank you,
Linda