go
mx2.subnetmask.net has one IP number , which also has a corresponding reverse pointer. postfix.poo-bas.com point to the same IP. cathead.org use this as a mailserver. subnetmask.net is a domain controlled by two nameservers on different IP networks. Incoming mail for subnetmask.net is handled by one mailserver at subnetmask.net themselves. subnetmask.net has one IP number , but the reverse is web1.reverse.net. mx2.subnetmask.net is hosted on a server in United States.

mx2.subnetmask.net
a records
 
+ 208.101.47.9 208.101.0.0/18 AS36351 -
+ --- -

subnetmask.net
a records
 
+ 208.101.21.58 208.101.0.0/18 AS36351 web1.reverse.net
+ --- web1.reverse.net
ns-soa records
ns.subnetmask.net
+ 208.101.21.58 208.101.0.0/18 AS36351 web1.reverse.net
+ --- web1.reverse.net
ns records
ns.reverse.net
+ 66.225.200.5 66.225.192.0/18 AS23352 -
+ --- -
ns.subnetmask.net
+ 208.101.21.58 208.101.0.0/18 AS36351 web1.reverse.net
+ --- web1.reverse.net
mx records
mx1.subnetmask.net
+ 208.101.47.8 208.101.0.0/18 AS36351 -
+ --- -
ip numbers of host
208.101.47.9
ptrs of ip numbers
mx2.subnetmask.net
ip numbers using ptr to this host
208.101.47.9
hostnames sharing ip with a-records
postfix.poo-bas.com
domains using this as mailserver
cathead.org
domains using this as mailserver under another name
poo-bas.com