Robtex

Up: 103.253.48.0/21
Can't show all results, try to descend to a more specific CIDR
Down left: 103.253.52.0/23
Down right: 103.253.54.0/23
(Some of the IP numbers are capped at 3 entries)

IP	Type	Hostname
103.253.52.2	A+PTR	mail1.basepen.com
103.253.52.2	A	basepen.com
103.253.52.8	A+PTR	mail1.geolevis.com
103.253.52.8	A	geolevis.com
103.253.52.12	PTR	mta12.echo.fineecho.com
103.253.52.12	A	errsale.com
103.253.52.12	A	cricarb.com
103.253.52.14	A+PTR	mail1.thornapp.com
103.253.52.26	A+PTR	mail1.revivalcard.com
103.253.52.26	A	revivalcard.com
103.253.52.38	A+PTR	mail1.onanalyst.com
103.253.52.38	A	onanalyst.com
103.253.52.50	A+PTR	mail1.seaomatic.com
103.253.52.50	A	seaomatic.com
103.253.52.56	PTR	mta56.echo.fineecho.com
103.253.52.56	A	mail1.wbrk.slpmt.net
103.253.52.56	A	aln.myvinmail.com
103.253.52.100	A	propiggy.com
103.253.52.167	A+PTR	smtp1-1.newtrendz.asia
103.253.52.167	A	newtrendz.asia
103.253.52.168	A+PTR	smtp1-1.koofi.in
103.253.52.168	A	koofi.in
103.253.52.176	A+PTR	smtp1-1.sunassets.in
103.253.52.176	A	sunassets.in
103.253.52.184	A+PTR	smtp1-1.e2kart.info
103.253.52.184	A	e2kart.info
103.253.52.205	PTR	mail1.couponsonclick.com
103.253.52.205	A	cps1.myvinmail.com
103.253.52.205	A	cps.myvinmail.com
103.253.52.211	A+PTR	mail1.tackmil.com
103.253.52.211	A	tackmil.com
103.253.52.230	A+PTR	mail1.nutrivitalsrush.com
103.253.52.230	A	exm.myvinmail.com
103.253.52.249	A+PTR	mail1.fleegogo.com
103.253.52.249	A	mail.freenewsletter.co.in
103.253.52.249	A	mail.fleegogo.com
103.253.53.41	A+PTR	mail1.netperl.com
103.253.53.41	A	mail.netperl.com
103.253.53.97	A+PTR	mail1.globalsamachar.in
103.253.53.97	A	mail.globalsamachar.in
103.253.53.115	PTR	mail1.invitinginbox.com
103.253.53.115	A	inb.myvinmail.com
103.253.53.115	A	inb1.myvinmail.com
103.253.53.118	A+PTR	multi118.nx.pointrays.com
103.253.53.177	A+PTR	mail1.cloudleep.com
103.253.53.177	A	mail.cloudleep.com
103.253.53.188	A+PTR	multi188.nx.pointrays.com
103.253.53.241	A+PTR	qmail1.royaldomaindns.net
103.253.54.46	PTR	mail46.aezcat.net
103.253.54.46	A	nwtrck.perlcafe.com
103.253.55.49	A+PTR	mail1.leegago.com
103.253.55.49	A	mail.leegago.com
103.253.55.82	PTR	mail1.vinfy.co.in
103.253.55.82	A	vfy.myvinmail.com
103.253.55.82	A	vfy1.myvinmail.com
103.253.55.100	PTR	mail1.acebotbay.com
103.253.55.100	A	abt1.myvinmail.com
103.253.55.100	A	abt.myvinmail.com
103.253.55.101	PTR	mail5.ewealthss.com
103.253.55.101	A	ewt.myvinmail.com
103.253.55.101	A	ewt5.myvinmail.com
103.253.55.113	A+PTR	mail1.salesjio.com
103.253.55.113	A	mail.salesjio.com
103.253.55.113	A	mail.staple-mail.com