> effective immediately all attachments will be deleted from emails
> no access to the web for browsing or ftp (Dec 24 to Jan 4)
> all modems to be unpluged (Dec 24 to Jan 4)
> no emails internal or external (Dec 24 to Jan 4)

Effective immediately: Noone should bother coming to work (Dec 24 to Jan 4)

The fact that no technology more advanced than a pencil eraser will be available due to millenium paranoia means that noone will be realistically expected to perform any actual work.

Given all the free time not spent doing the above activities, people are going to be really bored at your company (Dec 24 to Jan 4)