I have two large proxy email groups totalling in 5000 users.
I blast (1 email a day) your proxy for 2$ per blast; bulk discount is available.
If your proxy is fresh you should see good results, I have also noted that other proxy lists publish my blasted proxies on their lists.
This means there is multiplicator effect. On top of that will I send your proxy to a small number of minor email lists which also belong to me.