i have almost 25 email accounts but i only use 2 account one on yahoo and 2nd on gmail. and i think gmail is more fast then yahoo but the new change on gmail makes its really Slow.
I have around 5 in that 4 are from Gmail and Google Apps and 5th one is from hotmail (with my own domain name).
I think the topic starter is just curious, maybe he got lots of emails. Me, i got about 10 email addresses. But of course, i got a main email address.