At one time I frequently changed ISP and got fed up with having to tell dozens of people each time about the new email address. The solution I've used for some years is to get a "lifetime email address"; an address that redirects mail to wherever you actually are. There are several places to get these; the one I use is at http://www.pobox.com and costs me $15 per year. You can try one out for a month, free.
The only problem with using the same address for a long time - made worse by having a 2-character user ID - is that the spammers find you pretty quickly. I now get anything up to 100 spams a day. However, pobox have just added a spam filter to their basic service, at no extra cost. This seems to be doing a splendid job; I'm getting virtually no spams at all. It's better than any solution you can run on your own computer as it removes the mail at their end, so you don't need to download it to examine it. I can now happily give my address to anyone without fear of being deluged by a new wave of UCE (Unsolicited Commercial Email).
So I'd recommend the pobox.com service to anyone with a spam problem or who regularly changes provider.
P.S. I don't get paid for endorsing them.
-- GT