OK, after reading just about every post on the internet, I can't find a solution to my problem. I have 2 AD DC's (1 master, 1 secondary), both running server 2008 R2. I have an Exchange server running same OS and Exchange 2010 (no SP1). I can receive mail from anyone and I can send mail to about 90% of the world. For some reason, when i try to send to yahoo, and a couple local servers, I get delivery delayed for about a day or 2, then delivery failed. I tested the server on testexchangeconnectivity.com and everything passed except SPF record (not sure what this is.
I have public DNS servers (Linux / Bind) because I run hosting, and the public records are good. I have DNS on my AD servers and I don't think they are resolving properly. If I do "nslookup yahoo.com" I get the correct response, but if I do "nslookup", then "set q=mx", then "yahoo.com" I get "cannot resolve server"
Any help would be greatly appreciated.