When I changed from AOL I was offered the chance of keeping my email addresses for a monthly fee - sort of piggybacking the AOL through my new ISP.
I can't remember how much it was - but I didn't choose to pay it.
Instead, I set up web-based email addresses (gmail) before I started the switch. Informed all my contacts of my address, but still had the AOL for about 6 weeks, so anybody I missed could contact me.
It worked well - now I keep the gmail addresses no matter who my ISP is.
dunno if this will help you or not mycats as had a few beers at the moment but in my experiance when I have left an isp always seem to get e mails for months and months afterwoods , I have left ntl about 3 months ago and got conneted to sky and am using firefox but when I go to outlook I always get mails from my old adress but cant send mails
i had aol until about a month ago, but they do a thing called "Bring your own connection" i dont use it, but my wife still uses her old aol software and connects as she used to, no charges as yet.