You can use Charon to check to see if your proxies are any good, this way you will not have to check each one individually by hand. This program will keep your lists organized as well for you. You can download the software here, it is free to use.

http://www.freedownloadscenter.com/N..._Download.html

Just keep in mind that with mailing software you will using mostly socks 4/5 proxies and not HTTP (ports 80, 8080, 8088,3128). 3128 is commonly called a gopher proxy and sometimes can be set as a socks so you can try them still if you like. The most common socks proxy port is 1080, however you will find lists that will have some off the wall number assigned as the port, which in most cases is a zombie bot (socks proxy computer that is infected with a virus that makes it relay mail) Keep these lists even if they come up as no good, that same proxy can work the next day for you if that person is online with there computer.