When certain people email us, they get this error: 550 domain has demonstrably bogus mx records.
We have bought the domain, and have dns setup for it. It's been running for years and a while back updated to sme7. We haven't had any problems until now.
There is a valid PTR record setup for reverse dns.
The server hasn't restarted in several months, I'm going to bounce it today to see if that helps. Any suggestions would be great!
If you want to know the domain name, you can possibly im me on here or ask for my email.