go
mail.sina.de has one IP number , which also has a corresponding reverse pointer. mail.studsvik.de point to the same IP. sina.de is a domain controlled by three nameservers at eplan.net. Two of them are on the same IP network. Incoming mail for sina.de is handled by three mailservers. All of them are on the same IP network. mail.sina.de is hosted on a server in Germany.

mail.sina.de
a records
 
+ 80.245.67.34 80.245.64.0/20 AS24884 -
+ --- -

sina.de
ns-soa records
ns.eplan.net
+ 80.245.65.100 80.245.64.0/20 AS24884 -
+ --- -
ns records
ns.eplan.net
+ 80.245.65.100 80.245.64.0/20 AS24884 -
+ --- -
ns1.eplan.net
+ 80.245.66.100 80.245.64.0/20 AS24884 mailsrv2.eplan.net
+ --- mailsrv2.eplan.net
ns2.eplan.net
+ 217.29.33.162 217.29.32.0/20 AS16188 -
+ --- -
mx records
mailsrv1.eplan.net
+ 80.245.65.13 80.245.64.0/20 AS24884 -
+ --- -
mailsrv2.eplan.net
+ 80.245.65.38 80.245.64.0/20 AS24884 -
mail.studsvik.de
+ 80.245.67.34 80.245.64.0/20 AS24884 mail.sina.de
+ --- mail.sina.de
ip numbers of host
80.245.67.34
ptrs of ip numbers
mail.sina.de
ip numbers using ptr to this host
80.245.67.34
hostnames sharing ip with a-records
mail.studsvik.de
domains using this as mailserver under another name
sina.de
studsvik.de