go
www.trustico.com has one IP number , but the reverse is trustico.com. mail.trustico.com point to the same IP. trustico.com is a domain controlled by three nameservers. All of them are on different IP networks. Incoming mail for trustico.com is handled by two mailservers at trustico.com themselves having a total of three IP numbers. Two of them are on the same IP network. trustico.com has one IP number. www.trustico.com is hosted on a server in United States.

www.trustico.com
a records
 
+ 64.21.21.236 64.21.0.0/17 AS8001 trustico.com
+ --- trustico.com

trustico.com
a records
 
+ 64.21.18.72 64.21.0.0/17 AS8001  
+ ---  
ns-soa records
ns1.ssl-processing.com
+ 64.21.21.232 64.21.0.0/17 AS8001 -
+ --- -
ns records
ns1.telstra.net
+ 139.130.4.5 139.130.0.0/16 AS1221 -
+ --- -
ns1.ssl-processing.com
+ 64.21.21.232 64.21.0.0/17 AS8001 -
ns2.ssl-processing.com
+ 64.247.58.128 64.247.0.0/18 AS8001  
+ ---  
mx records
postoffice.telstra.net
+ 203.50.40.137 203.48.0.0/14 AS1221 pit-postoffice.telstra.net
+ --- pit-postoffice.telstra.net
+ 203.50.90.137 203.48.0.0/14 AS1221 exi-postoffice.telstra.net
+ --- exi-postoffice.telstra.net
mail.trustico.com
+ 64.21.21.236 64.21.0.0/17 AS8001 trustico.com
+ --- trustico.com
ip numbers of host
64.21.21.236
ptrs of ip numbers
trustico.com
hostnames sharing ip with a-records
mail.trustico.com
domains using this as mailserver under another name
trustico.com