Not worth doing unless you have the computer know-how to do a proper DNS attack, hijacking a whole load of accounts to send tens of thousands of e-mails. Twenty of us spamming them is not going to make the slightest difference (unfortunately it doesn't work quite like sending the BNP leaflet back to its return address without postage, but with a house-brick enclosed - obviously simply because you think they might be deeply interested in house bricks, no malicious intent intended).