Justiciar
Whichever ISP you use, or whichever "new" address you set up, sooner or later it will leak out and spam will start to arrive.
At that point, the question is "Run, or Filter?" If you change your e-mail address and dump the old one, that has problems of its own.
What I've done, and works fairly well, is to set up a different, totally secret e-mail address that receives filtered mail. That one's safe, and nobody knows it.
Then, I bought a couple of domains (well, more actually, but mostly for official purposes) each with e-mail forwarding and 20 addresses plus an "all other mail goes here". They cost just over £3 a year, which I reckon I can afford. (I use Fasthosts as registrar - easy to do online). I use one for close friends and family. For people and sites I don't trust fully, I create a specific address for that person/site - so, for example, I have
[email protected] and
[email protected]. Those addresses aren't specified on keefsspamtrap.org - the "all other mail" feature handles them.
keefsspamtrap forwards to Spamcop, which filters the mail and sends me the expurgated version. The family one forwards straight to the secret address.
If the problem gets too bad on a specific address, I just dump that address (or create a rule for it). The spam disappears into a black hole; genuine writers get their message back telling them that address is no longer in use.
That's a lot cheaper and a lot more flexible than changing ISP. I change ISP based on reliability and performance.