About 10pm central time on 11/13/19, I updated the mx records for this domain. The domain is registered at goDaddy and from the goDaddy admin, it is pointed at 5 infinityFree name servers. They are: ns1.byet.org ns2.byet.org ns3.byet.org ns4.byet.org ns5.byet.org
Since the mx update on 11/13, all but one of these name servers are returning the correct mx records. ns4.byet is not. As a result, email delivery is failing intermittently.
Thanks for the reply. Yep, I have done that. And 4 of the 5 infinity free name servers are returning the correct mx records. So I don’t think it’s a configuration issue; but rather a problem with that one nameserver.
Hmm, very strange, it does indeed look like ns4 is returning the wrong MX record. I’m going to have someone look into this.
In the mean time, you can safely remove ns4.byet.org from your domain name. Your domain name can safely operate using only 4 nameservers, and this will ensure all DNS servers used will return consistent results.