Robtex

Up: 64.72.224.0/23
Can't show all results, try to descend to a more specific CIDR
Down left: 64.72.224.0/25
Down right: 64.72.224.128/25
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
64.72.224.3	A+PTR	m3.comm100email1.com
64.72.224.6	A+PTR	m1.comm100email2.com
64.72.224.11	A+PTR	m2.comm100email3.com
64.72.224.12	A+PTR	m3.comm100email3.com
64.72.224.15	A+PTR	m2.comm100email4.com
64.72.224.19	A+PTR	m2.comm100email5.com
64.72.224.27	A	mail.mipps.com
64.72.224.34	A	enterprise.mipps.com
64.72.224.36	A	www2.mipps.net
64.72.224.38	A+PTR	m1.comm100email10.com
64.72.224.38	A	www3.mipps.net
64.72.224.39	A+PTR	m2.comm100email10.com
64.72.224.40	A+PTR	m3.comm100email10.com
64.72.224.41	A+PTR	m4.comm100email10.com
64.72.224.42	A+PTR	m1.comm100email11.com
64.72.224.42	A	syslog.mipps.net
64.72.224.43	A+PTR	m2.comm100email11.com
64.72.224.43	A	sav-l01-r02.mipps.net
64.72.224.43	A	atlas.mipps.net
64.72.224.61	A	m4.comm100email15.com
64.72.224.69	A+PTR	m4.comm100email17.com
64.72.224.74	A	m1.comm100email19.com
64.72.224.77	A+PTR	m4.comm100email19.com
64.72.224.86	A	m1.comm100email22.com
64.72.224.87	A	m2.comm100email22.com
64.72.224.88	A	m3.comm100email22.com
64.72.224.90	A+PTR	m1.comm100email23.com
64.72.224.93	PTR	m4.comm100email23.com
64.72.224.119	A+PTR	m6.comm100edm1.com
64.72.224.121	A+PTR	m8.comm100edm1.com
64.72.224.139	A+PTR	m2.comm100edm4.com
64.72.224.140	A	m3.comm100edm4.com
64.72.224.141	A	m4.comm100edm4.com
64.72.224.146	A+PTR	m1.comm100edm5.com
64.72.224.149	A	m4.comm100edm5.com
64.72.224.151	A	m6.comm100edm5.com
64.72.224.153	A	m8.comm100edm5.com
64.72.224.154	A+PTR	m1.comm100edm6.com
64.72.224.156	A	m3.comm100edm6.com
64.72.224.169	PTR	m8.comm100edm7.com
64.72.224.170	A	m1.comm100edm8.com
64.72.224.176	PTR	m7.comm100edm8.com
64.72.224.177	A+PTR	m8.comm100edm8.com
64.72.224.217	PTR	m0.comm100email25.com
64.72.224.230	A+PTR	mail.comm100.com
64.72.224.239	A	comm100reg.com
64.72.224.248	PTR	comm100emailticket.com
64.72.224.249	A	comm100.info