Warning: I may not be quite understanding how Google defines ‘30 days,’ so this might not be quite right, but… it seems fairly straightforward to me.
Monday, 10-30-06, I had nearly 9700 spam messages in my spam folder in my Gmail account. Tuesday, Gmail showed only 8800 messages in that folder.
This means that, at some point in late September, I received approximately 900 spam messages in one day.
Sheesh.