go
mail.02.net has one IP number , but the reverse is mail.o2.co.uk. mail.02.co.uk, mail.o2.co.uk and smtp.o2.co.uk point to the same IP. 02.net, 02.co.uk, o2.co.uk and genie.co.uk use this as a mailserver. 02.net is a domain controlled by four nameservers at 02.net themselves. Some of them are on the same IP network. Incoming mail for 02.net is handled by one mailserver also at 02.net. mail.02.net is hosted on a server in United Kingdom.

mail.02.net
a records
 
+ 82.132.141.69 82.132.128.0/20 AS29180 mail.o2.co.uk
+ --- mail.o2.co.uk

02.net
ns-soa records
dns0.02.net
+ 193.113.200.200 193.113.0.0/16 AS2856 -
+ --- -
ns records
dns0.02.net
+ 193.113.200.200 193.113.0.0/16 AS2856 -
+ --- -
dns1.02.net
+ 193.113.200.201 193.113.0.0/16 AS2856 -
dns2.02.net
+ 216.239.206.21 216.239.192.0/19 AS1273  
+ ---  
dns3.02.net
+ 216.239.206.22 216.239.192.0/19 AS1273  
mx records
mail.02.net
+ 82.132.141.69 82.132.128.0/20 AS29180 mail.o2.co.uk
+ --- mail.o2.co.uk
ip numbers of host
82.132.141.69
ptrs of ip numbers
mail.o2.co.uk
ip numbers using ptr to this host
82.132.141.70
hostnames sharing ip with a-records
mail.02.co.uk
mail.o2.co.uk
smtp.o2.co.uk
domains using this as mailserver
02.co.uk
02.net
genie.co.uk
o2.co.uk