go
public1.mx.protgp.com, public2.mx.protgp.com and private.mx.protgp.com are subdomains to this hostname. protgp.com is a domain controlled by two nameservers at protgp.com themselves. They are on different IP networks. Incoming mail for protgp.com is handled by one mailserver at mx.protgp.com. protgp.com has one IP number.

protgp.com
a records
 
+ 66.172.95.136 66.172.64.0/19 AS6408  
+ ---  
ns-soa records
ns1.protgp.com
+ 66.28.198.1 66.28.196.0/22 AS174 -
+ --- -
ns records
ns1.protgp.com
+ 66.28.198.1 66.28.196.0/22 AS174 -
+ --- -
ns2.protgp.com
+ 69.56.160.50 69.56.128.0/17 AS21844 32.a0.3845.static.theplanet.com
+ --- 32.a0.3845.static.theplanet.com
mx records
public1.mx.protgp.com
+ 66.172.95.60 66.172.64.0/19 AS6408 -
+ --- -
subdomains
private.mx.protgp.com
public1.mx.protgp.com
public2.mx.protgp.com