I've been reading articles on blogs like zenhabits and unclutterer lately and over the weekend I really started organizing all my online stuff, and it feels good. The best thing I've done is made it so all my emails are received via gmail. I have my main gmail account for personal stuff, PayPal, eBay etc, and then added a couple of POP3 accounts for some of my bigger sites. What's awesome is (which I didn't realize) is that you can reply to people and they just see the email from your POP account, not your gmail. One thing I've got from this too is realizing that I receive so few useful emails. Most of my emails were like "renew this domain" etc, but using labels and filters in gmail I've made it so only the real important stuff is shown in the Inbox with the rest of it being put under folders etc. Not sure why I'm posting this, but knowing I can access all my emails from anywhere is a good feeling.
I know what you mean. The exact same "Renew Your Domain" mails were coming to me, aswell as a lot of other annoying junk. I've sorted them out now and it's much better!