go
mailhost.promperu.gob.pe has one IP number , which also has a corresponding reverse pointer. correo.perumoda.com, mailhost.siicex.gob.pe and correo2.prompex.gob.pe point to the same IP. promperu.gob.pe use this as a mailserver. promperu.gob.pe is a domain controlled by two nameservers at telmex.net.pe. They are on different IP networks. Incoming mail for promperu.gob.pe is handled by one mailserver at promperu.gob.pe themselves. mailhost.promperu.gob.pe is hosted on a server in Peru.

mailhost.promperu.gob.pe
a records
 
+ 200.62.228.231 200.62.224.0/21 AS12252 correo2.prompex.gob.pe
+ --- correo2.prompex.gob.pe
+ --- mail.prompex.gob.pe
+ --- -
+ --- correo.perumoda.com

promperu.gob.pe
ns-soa records
ns1.telmex.net.pe
+ 200.62.191.10 200.62.188.0/22 AS12252 -
+ --- -
ns records
ns1.telmex.net.pe
+ 200.62.191.10 200.62.188.0/22 AS12252 -
+ --- -
ns2.telmex.net.pe
+ 200.24.191.10 200.24.184.0/21 AS12252 -
mx records
mailhost.promperu.gob.pe
+ 200.62.228.231 200.62.224.0/21 AS12252 correo2.prompex.gob.pe
+ --- correo2.prompex.gob.pe
+ --- mail.prompex.gob.pe
+ --- -
+ --- correo.perumoda.com
ip numbers of host
200.62.228.231
ptrs of ip numbers
correo.perumoda.com
correo2.prompex.gob.pe
mail.prompex.gob.pe
mailhost.promperu.gob.pe
ip numbers using ptr to this host
200.62.228.231
hostnames sharing ip with a-records
correo.perumoda.com
correo2.prompex.gob.pe
mailhost.siicex.gob.pe
domains using this as mailserver
promperu.gob.pe
domains using this as mailserver under another name
perumoda.com
prompex.gob.pe
siicex.gob.pe