Would be kind of fun to get this in email. Kind of like word of the day.
Edit: they do have a RSS feed and other ways to get a daily theorem from their Resources page [1]
[1] [ http://www.theoremoftheday.org/Resources/Resources.htm ]
Though are you getting the full pdf's? I'm using Sage and a lot are linking to PDF's with "A newer version of this theorem description is now being hosted at: www.theoremoftheday.org/Theorems.html"
Also some are linking just to the home page. I'm wondering if this is just me or you're getting the same.
My apologies. I should have checked that the RSS is returning valid links.