Robtex

Up: 64.50.144.0/20
Can't show all results, try to descend to a more specific CIDR
Down left: 64.50.152.0/22
Down right: 64.50.156.0/22
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
64.50.152.24	A+PTR	transactional.emailboster.com
64.50.152.134	A+PTR	mailer4.marketer365.com
64.50.152.183	A+PTR	mailer1.yillou.net
64.50.153.249	A	64-50-153-249.client.dsl.net
64.50.155.4	A	zebratrackz.com
64.50.155.4	A	simplycast.mobi
64.50.155.4	A	marketinggalaxy.com
64.50.155.28	A+PTR	ns2.scsend.net
64.50.155.29	A+PTR	ns1.scsend.net
64.50.155.30	PTR	mail2.simplycast.com
64.50.155.30	A	webmail.franchiseasaservice.org
64.50.155.30	A	mail.franchiseasaservice.org
64.50.155.32	PTR	app5.simplycast.com
64.50.155.33	A+PTR	app6.simplycast.com
64.50.155.50	PTR	www2.simplycast.com
64.50.155.50	A	social-mailer.com
64.50.155.50	A	crm-optin.com
64.50.155.53	PTR	mail1.simplycast.com
64.50.155.125	A	64-50-155-125.client.dsl.net
64.50.155.158	PTR	app.scsend.net
64.50.156.2	A+PTR	na2.scsend.net
64.50.156.16	A+PTR	na16.scsend.net
64.50.156.26	A+PTR	na26.scsend.net
64.50.156.36	A	na36.scsend.net
64.50.156.39	A	na39.scsend.net
64.50.156.54	A	na54.scsend.net
64.50.156.66	A+PTR	na66.scsend.net
64.50.156.73	PTR	scmc063.net
64.50.156.77	A	na77.scsend.net
64.50.156.91	A+PTR	na91.scsend.net
64.50.156.93	A	na93.scsend.net
64.50.156.94	A	na94.scsend.net
64.50.156.97	A+PTR	na97.scsend.net
64.50.156.102	A	na102.scsend.net
64.50.156.114	A+PTR	na114.scsend.net
64.50.156.116	A	na116.scsend.net
64.50.156.118	A	na118.scsend.net
64.50.156.121	A+PTR	na121.scsend.net
64.50.156.134	A	na134.scsend.net
64.50.156.142	A	na142.scsend.net
64.50.156.144	A+PTR	na144.scsend.net
64.50.156.146	A+PTR	na146.scsend.net
64.50.156.163	A+PTR	na163.scsend.net
64.50.156.167	A	na167.scsend.net
64.50.156.168	A+PTR	na168.scsend.net
64.50.156.179	A+PTR	na179.scsend.net
64.50.156.183	A	na183.scsend.net
64.50.156.192	A+PTR	na192.scsend.net
64.50.156.193	A+PTR	na193.scsend.net
64.50.156.194	A+PTR	na194.scsend.net
64.50.156.196	A	na196.scsend.net
64.50.156.201	A+PTR	na201.scsend.net
64.50.156.208	A+PTR	na208.scsend.net
64.50.156.209	A+PTR	na209.scsend.net
64.50.156.210	A+PTR	na210.scsend.net
64.50.156.216	A+PTR	na216.scsend.net
64.50.156.228	A	na228.scsend.net
64.50.156.250	A+PTR	na250.scsend.net
64.50.157.152	A	nb152.scsend.net
64.50.157.193	A	nb193.scsend.net
64.50.158.116	A	nc116.scsend.net
64.50.159.23	A	nd23.scsend.net
64.50.159.99	A	nd99.scsend.net