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mail1.lawpga.com has one IP number , which also has a corresponding reverse pointer. lawpga.com use this as a mailserver. lawpga.com is a domain controlled by two nameservers at covad.net. They are on different IP networks. Incoming mail for lawpga.com is handled by two mailservers at lawpga.com themselves. They are on different IP networks. mail1.lawpga.com is hosted on a server in United States.

mail1.lawpga.com
a records
 
+ 12.4.213.148 12.0.0.0/9 AS7018 -
+ --- -

lawpga.com
ns-soa records
 
+   AS?  
+ ---  
ns records
ns1.covad.net
+ 216.251.45.139 216.251.32.0/20 AS14116 -
+ --- -
ns2.covad.net
+ 64.29.158.54 64.29.144.0/20 AS30447 -
mx records
mail1.lawpga.com
+ 12.4.213.148 12.0.0.0/9 AS7018 -
+ --- -
mail.lawpga.com
+ 208.118.165.74 208.118.160.0/19 AS22925  
+ ---  
ip numbers of host
12.4.213.148
ptrs of ip numbers
mail1.lawpga.com
ip numbers using ptr to this host
12.4.213.148
216.142.110.51
domains using this as mailserver
lawpga.com