Amount of Mail going through the machines:
Ordinary week day - about 80K.
Ordinary Monday - 130-140K.
Last Monday (first day of Christmas pressure) - 296K.
Yesterday (busiest day of year) - 270K minimum on our shift plus 163K that Mornings did. No idea yet on Nights.
This is why I tend to sleep through the actual Christmas Day a lot. :)
Edit/Update: we're still running the mail from yesterday right now. Add another 308K onto yesterday's total to cover for the amount ran from 6am to 5pm today - and we're still going!