Hi,
I use PLESK 11 on one of my servers, and use NS.mydomain & NS1.mydomain, everything works fine, DNS Zones are OK, reverse DNS is OK...
Except on MXTOOLBOX this :
SMTP Valid Hostname > Reverse DNS is not a valid Hostname
SMTP Reverse > DNS Mismatch OK - 195.154.XXX.XXX resolves to...