I recently messed my IP and had to get a new one and have been having MAJOR issues with my DNS settings, Through the Registrar NOT V-min
So I have a couple links that might help some of you out.
DKIM Check: http://dkimcore.org/tools/
SPF Check: http://www.kitterman.com/spf/validate.html?
Now I've found that my PTR Actually needs to be set be my VPS Provider (And maybe my NAMESERVER, I'll update on that when I find out)
Hope it helps.