go
mail.pcdi.com point to 208.49.241.161.

mail.pcdi.com
a records
 
+ 208.49.241.161 208.49.0.0/16 AS3549 208.49.241.161.pcdi.com
+ --- 208.49.241.161.pcdi.com

208.49.241.161.pcdi.com
ptr records
 
+ 208.49.241.161 208.49.0.0/16 AS3549 -
+ --- -
ip numbers of host
208.49.241.161
ptrs of ip numbers
208.49.241.161.pcdi.com
hostnames sharing ip with a-records
mail.pcdi.com
domains using this as mailserver
gotopcdi.com
pcdi.com
step2pcdi.com
steptopcdi.com