I think my dev server got blacklisted... help!

I have a dev server that was sending an email every minute for testing and analysis. After about 3 hours, I stopped getting the emails.

I guess there is a spam filter that started catching and rejecting email from that server. Typically this would be a good thing, but I really need those emails.

I whitelisted the server and the from email address... but, no dice. Is there any way I can get that server whitelisted?

Thanks!