Not sure if opendns has option to change the RBL behavior (maybe in paid version or if you create an account) but I've only trusted my own dns servers for years & highly recommend anyone running a mail server to run their own too even if just caching-only BIND which isn't too resource heavy at all. Not sure what you use (I wouldn't even trust my ISP's) but for anyone interested there are lots of how-to's about setting it up. There might even be one on here or maybe someone will make one.
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hMailServer build LIVE on my servers: 5.4-B2014050402
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