On September 22, 2014, NJ Transit's MyTix service sent an email with 3,667 addresses in the To: field. Here's a breakdown of all the domains.

mytix-domains.txt

2193 gmail.com
 386 yahoo.com
 168 hotmail.com
 158 aol.com
  60 me.com
  52 comcast.net
  49 verizon.net
  39 mac.com
  32 optonline.net
  18 msn.com
  18 icloud.com
  12 nyu.edu
  10 outlook.com
  10 gmail.con
   9 live.com
   7 yahoo.con
   7 udel.edu
   7 aim.com
   6 student.shu.edu
   6 fordham.edu
   6 att.net
   5 mail.montclair.edu
   5 deloitte.com
   4 ymail.com
   4 yahoo.co.in
   4 princeton.edu
   4 pfizer.com
   3 temple.edu
   3 tcnj.edu
   3 syr.edu
   3 optimum.net
   3 kpmg.com
   3 cornell.edu
   3 columbia.edu
   3 bucknell.edu
   3 bc.edu
   2 yahoo.co.uk
   2 squaremilecapital.com
   2 shu.edu
   2 sbcglobal.net
   2 saramax.com
   2 rocketmail.com
   2 ramapo.edu
   2 qq.com
   2 nhl.com
   2 nbcuni.com
   2 mindspring.com
   2 kean.edu
   2 hotmail.fr
   2 gmail.clm
   2 emc.com
   2 drew.edu
   2 cse.edu
   2 citi.com
   2 bu.edu
   2 brown.edu
   2 aya.yale.edu
   1 zislin.net
   1 younglandstores.com
   1 yohoo.com
   1 yahoo.pl
   1 yahoo.com.br
   1 yahoo.co
   1 yahoi.com
   1 woundedwarriorproject.org
   1 whatrickdid.com
   1 westwood-partners.com
   1 wellthapp.com
   1 weintraub.name
   1 webwhere.com
   1 vwsupply.com
   1 vwr.com
   1 vt.edu
   1 vosses.com
   1 visionfirst.com
   1 villanova.edu
   1 verisk.com
   1 vca.com
   1 vanderbilt.edu
   1 vanbridge.com
   1 uwalumni.com
   1 uw.edu
   1 usa.net
   1 us.luxottica.com
   1 upenn.edu
   1 untracht.com
   1 umusic.com
   1 umich.edu
   1 uga.edu
   1 ubm.com
   1 u3studios.com
   1 u.northwestern.edu
   1 tsiusa.com
   1 trlm.com
   1 trinitykai.com
   1 travelers.com
   1 trandon.com
   1 tnjtfay.com
   1 thinkso.com
   1 thinkdsignprint.com
   1 thejm.org
   1 thecinqs.com
   1 theblankpage.com
   1 thebaynes.com
   1 terpmail.umd.edu
   1 tawil.com
   1 susqu.edu
   1 student.fdu.edu
   1 streetlightmission.org
   1 stevens.edu
   1 stevefink.net
   1 steeltrader2.com
   1 starledger.com
   1 soluto.com
   1 snet.net
   1 smithmaran.com
   1 smitelli.com
   1 sleepstudio.com
   1 slackinc.com
   1 skidmore.edu
   1 sju.edu
   1 schultea.net
   1 scarletmail.rutgers.edu
   1 sc.com
   1 sabarese.com
   1 rwjms.rutgers.edu
   1 rutgers.edu
   1 rozhitsky.com
   1 rosetta.com
   1 romark.com
   1 rockfound.org
   1 roche.com
   1 robothaus.net
   1 rnjconsult.com
   1 rit.edu
   1 right.com
   1 richardquest.com
   1 reneatchison.com
   1 redpaperheart.com
   1 rdspas.com
   1 rcn.com
   1 rci.rutgers.edu
   1 ramabadran.com
   1 raffyd.com
   1 quinnipiac.edu
   1 pwmakes.com
   1 ptd.net
   1 prnkstr.com
   1 pouschinecook.com
   1 podttraining.com
   1 plentynyc.com
   1 pkaufmann.com
   1 pernod-ricard.com
   1 pentagram.com
   1 parigigroup.com
   1 pace.edu
   1 p2site.com
   1 ownerscorp.com
   1 orthonj.com
   1 optonline.bet
   1 oppenheimerfunds.com
   1 oikos.ws
   1 oberlinschools.org
   1 nyumc.org
   1 nyit.edu
   1 nyc.rr.com
   1 nsacpa.com
   1 nrinet.com
   1 novonordisk.com
   1 noven.com
   1 northstar-rs.com
   1 njit.edu
   1 nimrichter.com
   1 newschool.edu
   1 netscape.net
   1 my.fsu.edu
   1 muroffarch.com
   1 mugworx.com
   1 mufson.net
   1 mtwstudios.com
   1 mtm.com
   1 mshanken.com
   1 msasi.net
   1 moret.com
   1 moorjanicaribbean.com
   1 moodys.com
   1 montrosesoftware.com
   1 moma.org
   1 mofo.com
   1 mlssoccer.com
   1 metaphorpictures.com
   1 merrillcorp.com
   1 merkuryinnovations.com
   1 merck.com
   1 mdsol.com
   1 mdlz.com
   1 mcinally.com.au
   1 mccmgroup.com
   1 mccarter.com
   1 martinlange.com
   1 marriott.com
   1 marketsmedia.con
   1 manhattan.edu
   1 mallenbaum.com
   1 mail.saintpeters.edu
   1 mail.ru
   1 mail.mcgill.ca
   1 madriver.com
   1 macquarie.com
   1 loyola.edu
   1 loupedigital.com
   1 lizlimoline.com
   1 live.esu.edu
   1 live.co.uk
   1 limcollege.edu
   1 lgenv.com
   1 lexisnexis.com
   1 level02.sent.com
   1 lawhusick.com
   1 langan.com
   1 labaton.com
   1 kurthines.com
   1 kupfer.us
   1 ksu.edu
   1 koukourdelis.com
   1 kornferry.com
   1 kinney.me
   1 kings.edu
   1 kevinpjones.com
   1 kenyon.com
   1 kellyaugustine.com
   1 kbsp.com
   1 kantarhealth.com
   1 jpmchase.com
   1 josephcoston.com
   1 johnbrophymusic.com
   1 jhu.edu
   1 jhpii.com
   1 jetblue.com
   1 jeanieko.com
   1 jcca.org
   1 jbcstyle.com
   1 jazebra.com
   1 its.jnj.com
   1 interactivedata.com
   1 integritasgrp.com
   1 infosys.com
   1 iese.edu
   1 iempact.com
   1 ieee.org
   1 holyangels.org
   1 hntb.com
   1 hillwallack.com
   1 highlifellc.com
   1 hfpmlaw.com
   1 hetco.com
   1 hellman.net
   1 hbgusa.com
   1 haverford.edu
   1 hartwick.edu
   1 hartford.edu
   1 handcraftmfg.com
   1 hakins.com
   1 hafeleamericas.com
   1 gta-travel.com
   1 gse.rutgers.edu
   1 gs.com
   1 groupm.com
   1 greenblacks.net
   1 gnail.com
   1 gmx.net
   1 gmal.com
   1 gmaill.com
   1 gmaiil.com
   1 gilt.com
   1 gfigroup.com
   1 gettyimages.com
   1 georgetown.edu
   1 georgebaier.com
   1 gc.cuny.edu
   1 gardenstateyoga.com
   1 gallant.com
   1 g.holycross.edu
   1 futuromediagroup.org
   1 frostproductions.biz
   1 friars.providence.edu
   1 fournorths.com
   1 fitnyc.edu
   1 fieldoperations.net
   1 ferreiraweb.com
   1 fdu.edu
   1 fdic.gov
   1 fastmail.fm
   1 fandm.edu
   1 expressjet.com
   1 evercore.com
   1 esri.com
   1 erlichson.net
   1 equitone.com
   1 enumeral.com
   1 entirelyamelia.com
   1 eleqtra.com
   1 ekucharz.com
   1 eksuccess.com
   1 edlings.org
   1 edelman.com
   1 diversitycomm.com
   1 disney.com
   1 dinsmorecap.com
   1 dimensioneleven.com
   1 dfa.state.ny.us
   1 deutsche-eco.com
   1 delorenzodesign.com
   1 dcas.nyc.gov
   1 dbmind.com
   1 cynopsis.com
   1 cybermaloney.com
   1 csail.mit.edu
   1 crowdflipr.com
   1 covercopy.com
   1 covanta.com
   1 cotyinc.com
   1 cortland.edu
   1 copyleft.net
   1 conceptsnyc.com
   1 concast.net
   1 commvault.com
   1 commdevices.com
   1 comdcpa.com
   1 comcast.met
   1 colpal.com
   1 cisco.com
   1 childrensaidsociety.org
   1 cgsh.com
   1 cbs.com
   1 canisius.edu
   1 caldwellandwalsh.com
   1 caisgroup.com
   1 buffalo.edu
   1 bryant.edu
   1 brandeis.edu
   1 bms.com
   1 bmgm.us
   1 bm.com
   1 blackrock.com
   1 binghamton.edu
   1 besenretail.com
   1 benlowy.com
   1 becker.am
   1 bangworld.com
   1 babycenter.com
   1 babson.edu
   1 avservices.net
   1 att.com
   1 astechgroup.com
   1 arkivmusic.com
   1 arena1.com
   1 ap3d.net
   1 amyneiman.com
   1 alumni.wfu.edu
   1 alumni.nd.edu
   1 alumni.duke.edu
   1 alpinethinking.com
   1 alpinebiz.com
   1 alcatel-lucent.com
   1 aimeejolson.com
   1 agedinwood.com
   1 adanunezlaw.com
   1 acolyteled.com
   1 accenture.com
   1 aboutdci.com
   1 ablog.org
   1 abc.com
   1 94by50.com
   1 2xist.com
   1 27thand5th.com