In future versions of our websites you will be able to check and claim multiple addresses using our automated site.
Right now we offer a completely free service for people such as yourself in regards to checking your bulk addresses.
If you could send me the 3000 addresses list... each one will be checked for CLAMS for free for you.
Alternatively, you could download the CLAM CLIENT and it would automatically do this for you. We understand a lot of people would rather not go through the hassle of syncing, trusting altcoin wallets and other such things.
Keep in mind that the address had to be in use ON May 12, 2014 & you need to have access to the private keys... sounds like you maybe sitting on a nice load of hidden coins.
We only need the public keys to do the checking for Clamcoins.
Don't forget your wallets "Change Addresses"