I've got a customer that we work with who can't receive our emails. When I do a NSLookup on a customer's domain in our network, it returns the incorrect MX record. Instead of mail.XX.net it returns a MX record of xx.net. Their IT admin told me to enter a static MX record to replace what I'm getting back. I don't know why I have to do that, but if it makes my boss and his boss happy (and communicating) then we'll do it. But first, I don't know how to do that (please help) and second I don't know why this is a problem in the first place. I did run a dnsstuff.com dnsreport on his domain, it passed everything but the "Mail" section (full failure). It passed the MX section, but not Mail. Again, not sure and neither is their IT admin. They are getting email from other sources because I can mail him from an outside email.
Thanks for your help, Stephen