Below is a list of most common ISP's (Internet Service Providers) outgoing SMTP Servers. Some ISP's do not allow their users to use a third party mail server to send outgoing mail. In that case you can use your ISP's outgoing SMTP Server.
| ISP (Internet Service Provider) | SMTP Server Host Name |
| Adelphia | smtp.blk.adelphia.net |
| Alltel | mail.alltel.net |
| AOL | smtp.aol.com |
| AT&T | mailhost.worldnet.att.net |
| AT&T Business Internet Service | mail.attbi.com |
| AT&T (Dialup) | smtp1.attglobal.net |
| BCPL | mail.bcpl.net |
| bellatlantic.net | smtpout.bellatlantic.net |
| BellSouth | mail.bellsouth.net |
| Bestweb | smtp.bestweb.net |
| BEV.net | smtp.bev.net |
| Blacksburg.net | smtp.blacksburg.net |
| BYU | nm.byu.edu |
| CalWeb | smtp.calweb.com |
| CBeyond (Atlanta) | mail.atl.cbeyond.com |
| Charm.net | smtp.charm.net |
| Charter Communications | smtp.charter.net |
| chicagonet.net | mail.chicagonet.net |
| Citizen's Internet | smtp.swva.net |
| Coastalnet | mail2.coastalnet.com |
| Columbia | smtp.columbia.edu |
| Comcast | smtp.comcast.net |
| Comcast / ATTBI | smtp.comcast.net |
| CompuServe 2000 | smtp.cs.com |
| CompuServe Classic | mail.compuserve.com |
| Concentric | smtp.concentric.net |
| Cox East | smtp.east.cox.net |
| Cox West | smtp.west.cox.net |
| Crosslink | smtp.crosslink.net |
| CU Boulder | eces.colorado.edu |
| DirecWay | smtp.direcway.com |
| EarthLink | mail.earthlink.net |
| Enter | smtp.enter.net |
| Ezy | smtp.ezy.et |
| FloydVA.net | mail.floydva.net |
| ibm.net | smtp1.ibm.net |
| interaccess.com | smtp.interaccess.com |
| ITOL | mail.itol.com |
| Juno | smtp.juno.com |
| Lycos | email.1stup.com |
| MCI2000 | mailrelay.internetmci.com |
| McLeodusa | email.mcleodusa.net |
| mediaone.net | smtp.ce.mediaone.net |
| Mindspring | smtp.mindspring.com |
| Mpower Communications | smtp.mpowercom.net |
| MSN | smtp.email.msn.com |
| netcom.com | smtp.ix.netcom.com |
| netexpress.net | netexpress.net |
| NetHere | mail.nethere.net |
| Netscape | smtp.isp.netscape.com |
| Netzero | smtp.netzero.net |
| NRVi.net | mail.nrvi.net |
| NTELOS | mail.ntelos.net |
| NYU.edu | is4.nyu.edu |
| Omega Communications | smtp.i-plus.net |
| PacBell | mail.pacbell.net |
| PeoplePC | mail.peoplepc.com |
| Prodigy | smtp.prodigy.net |
| PSI.net | relay.smtp.psi.net |
| PSINet | bbr0-f1.sna.com |
| PSU.edu | smtp.psu.edu |
| PTD.net | mail.ptd.net |
| Qwest Colorado Springs | pop.clsp.qwest.net |
| Qwest Denver | pop.dnvr.qwest.net |
| Qwest Idaho | pop.bois.qwest.net |
| Qwest Nebraska | pop.omah.qwest.net |
| Qwest New Mexico | pop.albq.qwest.net |
| Qwest Phoenix | pop.phnx.qwest.net |
| Qwest Tucson | pop.tcsn.qwest.net |
| RCN.com | smtp.rcn.com |
| Rider.edu | enigma.rider.edu |
| Road Runner (Hawaii) | smtp-server.hawaii.rr.com |
| Road Runner (San Diego) | mail.san.rr.com |
| SBC Global | smtp.sbcglobal.net |
| SBC Global Pacbell | smtp.pacbell.yahoo.com |
| SBC Global Prodigy | smtpauth.prodigy.net |
| SBC Global SWBell | smtp.swbell.yahoo.com |
| SBC Global Yahoo! | smtp.sbcglobal.yahoo.com |
| SDSU | rohan.sdsu.edu |
| Shentel | smtp.shentel.net |
| SpeakEasy | mail.speakeasy.net |
| SprintPCS | smtp.sprintpcs.com |
| Sysnet | mail.sysnet.net |
| telocity.com | smtp.telocity.com |
| UCCS | smtp.uccs.edu |
| UCSD | smtp.ucsd.edu |
| ucsf.edu | mail.ucsf.edu |
| UMBC | smtp.gl.umbc.edu |
| velocityhsi.com | mail.velocityhsi.com |
| Verio | mail.verio.net |
| Verizon | outgoing.verizon.net |
| Verizon | smtpout.verizon.net |
| Virginia Tech | smtp.vt.edu |
| Waypoint | mail.wayport.net |
| Yahoo | smtp.mail.yahoo.com |
| XO Communications | mail.njd.xo.com |
| XO Communications | smtp.concentric.net |
| Ziplink | smtp.ziplink.net |
| ZNET | mail.znet.com |
