I do an independent query on smtp01-in.isheriff.com and it reports 69.64.127.243 as the published address.
It matters not what domain you start with if the ultimate test is to query an 'A' record for a given hostname.
I then do another independent query on smtp01-in.isheriff.com and it reports 67.23.41.24, as you expected.
The logical conclusion here is that the hostname has more than one IP Address, which is a perfectly legitimate reality for an SMTP server.
Do you have some authoritative information to the contrary that would demonstrate that 67.23.41.24 is the only valid IP Address for that hostname?