Xuzz

Stack Exchange uses subdomains for many of it's beta QA communities, and we somewhat regularly get posts from them -- but, because HN only shows the domain itself, telling which community it's from requires clicking the…

None, or almost none. I use Filters (or the equivalent in your email client) to file everything away.

Other (explain in comment!)

15 to 50: I can't always reply to everything important immediately, but I make sure I don't get too far behind.

None, or almost none. I manage to read everything people send me, and reply to what needs replies.

50 to 250: I reply to the important emails right away, but there's just too many to reply to them all.

2,000 or more: I'm close to declaring email bankruptcy. If it's really important, I'll read it and reply to it, but there's no chance I could even read everything I get.

Email Bankruptcy: I've declared email bankruptcy, sent out a message to re-send the email if it's still important, and I'll try and be better about replying quickly this time.

250 to 2,000: I read only what's important.