Adelphia  mail.adelphia.net
America Online (AOL)  smtp.aol.com
Atlantic Broadband  smtp.atlanticbb.net
AT&T (Broadband)  mail.attbi.com
AT&T (Dialup)  smtp1.attglobal.net
AT&T Worldnet  mailhost.worldnet.att.net or imailhost.worldnet.att.net
BCPL  mail.bcpl.net
Bellatlantic  gtei.bellatlantic.net or smtpout.verizon.net>
Bellatlantic.net  smtpout.bellatlantic.net
Bellsouth  mail.bellsouth.net 
Bestweb  smtp.bestweb.net
Bell Canada smtp.bellnet.ca and smtp10.bellnet.ca
BEV  smtp.bev.net
Blacksburg  smtp.blacksburg.net
Blazenet  smtp.blazenet.net
Cable One  mail.cableone.net
CAIS  smtp.cais.net
CAPU  smtp.capu.net
Charm.net  smtp.charm.net
Charter Communications  smtp.charter.net
Citizen's Internet  smtp.swva.net
Comcast  smtp.comcast.net
Compuserve  smtp.compuserve.com or smtp.site1.csi.com
Concentric.net  smtp.concentric.net 
Covad  smtp.covad.net 
Cox West  smtp.west.cox.net(west coast users)
Cox Central   smtp.central.cox.net (central users)
Cox East   smtp.east.cox.net(east coast users)
Cox Business  smarthost.coxmail.com
Crosslink  smtp.crosslink.net
DCANET  smtp-relay.dca.net
Delmarva Online  mail-gw.dmv.com
Delta Net  smtp.deltanet.com
Direcway  smtp.direcway.com 
DSL Extreme  smtp.dslextreme.com
Earthlink Network   mail.earthlink.net or smtp.earthlink.net 
Earthlink Network (International only)  ismtp.earthlink.net
Edge.net  mail.edge.net
Enter  smtp.enter.net
EROLS  mail.erols.com
Ezy  smtp.ezy.net
Flashcom  mail.flashcom.net or smtp.flashcom.net
Forthnet mailgate.forthnet.gr
Frontline.net  smtp.fcc.net
Full Channel  smtp.fullchannel.net
Gateway.net  smtp.Gateway.net
GTI  mail.gti.net
HotMail  mail.hotmail.com
IBM.Global net   smtp1.ibm.net 
ioNet Inc  mail.ionet.net
Integra  smtp.integra.net
Interaccess.com  smtp.interaccess.com
Internet America  mail.airmail.net
Internet Highway  smtp.ihwy.com
ITOL  mail.itol.com
Juno  smtp.juno.com
Mediacom  mail.mchsi.com
Mediaone.net  smtp.ce.medione.net
MegaPath  mail.megapathdsl.net
MCI  mailrelay.mciworldcom.net mailrelay.internetmci.com
Mindspring  smtp.mindspring.com
MSN  smtp.email.msn.com
Nauticom  mail.nauticom.net
Netcom   smtp.ix.netcom.com 
Netcom (Canada)  smtp.netcom.ca
Netscape  smtp.isp.netscape.com
NetZero  smtp.netzero.net
NYU.edu  smtp.nyu.edu
OLG.com  mail.olg.com
Omega Communications  smtp.i-plus.net
OPTOnline Internet Service  mail.optonline.net
Pacbell   mail.pacbell.net 
Patriot Media  smtp.patmedia.net
PeoplePC Online  mail.peoplepc.com
Pipeline  smtp.pipeline.com
Prodigy  smtp.prodigy.net
PSI.net  relay.smtp.psi.net
PTD.net  promail.ptd.net port 25
QIS  mail.qis.net
Qwest Internet Service  pop.dnvr.qwest.net
RCN  smtp.rcn.com
Rider.edu  enigma.rider.edu
RoadRunner  smtp-server.<your-region>.rr.com 
Rogers (CANADA) smtp.broadband.rogers.com
SBC Global  smtp.sbcglobal.net
SBC Global Yahoo  smtp.sbcglobal.yahoo.com
Smallville Communications   mail.toto.net
SNiP  mail.snip.net
Spectrum DSL  mail.webstable.com
SprintLink   smtp.a001.sprintmail.com 
Sprynet  m6.sprynet.com
Starpower  smtp.starpower.net
Sympatico  mailhost.sk.sympatico.ca
Telus smtp.telus.net
UMBC  smtp.gl.umbc.edu
USA.NET  mail.netaddress.usa.net
US Internet  smtp.usit.net
UUNet  mail.uu.net
Verizon Internet Services  outgoing.verizon.net or smtpout.verizon.net
Videotron relais.videotron.ca
Wide Open West  smtp.mail.wideopenwest.com
XO Communications  mail.njd.xo.com or smtp.concentric.net
Yahoo  smtp.mail.yahoo.com
Ziplink  smtp.ziplink.net