To use mIRC you have to connect to an IRC Network. The IRC networks consist of groups of servers in close contact with eachother. Several of such worldwide networks exist. The servers in a network maintain the contact between you and all other users. If you want to enjoy your IRC sessions it is important to find servers that work (fast) for you (ie. that are nearby to you) on networks with the athmosphere you like. mIRC comes with a rather complete list of servers but you can always download an updated version here, or select some additional ones from the lists below.

 IRC Networks.

 On this page we gathered together some recent lists of networks and their servers. Of most of the larger networks the most important servers are already included in mIRC's distribution files but when you need some additional ones to update your collection, this is the place to look :) We'd like to point to the mIRCLinks provided in these lists; click on a nearby server and mIRC will be launched by your browser and connect to the selected server! Of course you have to configure your www browser to work with mIRCLinks first! If a server refuses to connect you, just try another one! Most servers only accept local users or people living in the same state. 

DALnet - DALnet was created by The EFnet's #startrek users as a quiet place where they could run their channel without having to deal with op hacks and netsplits. But the people who run DALnet stress that its not just for trekkers anymore. DALnet is nicely quiet, well organized and one of the three main IRC networks. DALnet servers use port 7000. 

Canada, Ajax, Ont - durham.DAL.net 
Canada, Edmonton Alb - raptor.DAL.net 
EU, Finland, Espoo - xgw.DAL.net 
EU, Sweden, Lund - marvin.dal.net 
EU, Sweden, Stockholm - vogon.dal.net 
EU, United Kingdom, Bristol - liberator.DAL.net 
EU, United Kingdom, London - defiant.dal.net 
US, Arizona, Phoenix - scorpion.dal.net 
US, California, El Segundo - cyberverse.DAL.net 
US, California, Davis - davis.DAL.net 
US, California, San Jose - mindijari.DAL.net 
US, California, Santa Clara - spider.DAL.net 
US, California, San Diego - voyager.DAL.net 
US, Florida, Jacksonville - centurion.dal.net 
US, Indiana, Hebron - hebron.dal.net 
US, Missouri, St.Louis - stlouis.DAL.net 
US, North Carolina, Charlotte - uncc.DAL.net 
US, Ohio, Cleveland - barovia.dal.net 
US, Ohio, Toldeo - glass.DAL.net 
US, Oklahoma, Tulsa - webzone.dal.net 

DALnet Servers http://www.dal.net/servers/index.html
More DALnet Servers http://www.xmission.com/~dragon/dalnet/server.html

EFnet - Eris Free net is the largest IRC network with about 30.000 online users on an average day. Because of its massive size EFnet is having alot of problems with lag, netsplits, op hacking and various other things. But it is still the most popular IRC network. EFnet servers use port 6667. 

Canada, Magic - irc.magic.mb.ca 
US, AZ, Phoenix - irc.primenet.com 
US, AZ, Tucson - irc.blackened.com 
US, CA, Cupertino - irc.cris.com 
US, CO, Colorado - irc.colorado.edu 
US, IL, Chicago - irc.mcs.net 
US, IL, Chicago - irc.ais.net 
US, MO, Missouri - irc.mo.net 
US, OK, Oklahoma - irc.ionet.net 
US, TX, Houston - irc.phoenix.net 
US, VA, Herndon - irc.psinet.com 
US, America Online - irc02.irc.aol.com 

More EFnet Servers http://www.irchelp.org/irchelp/networks/servers/efnet.html

Undernet - Undernet is a good alternative to EFnet. It provides a friendly and stable IRC network. The Undernet is growing in size very rapidly due to the continous improvements to the servers and the information and help provided to its users. Undernet servers use port 6667. 

Canada, Quebec, Montreal - montreal.qu.ca.undernet.org 
Canada, Ontario, Toronto - toronto.on.ca.undernet.org 
Canada, BC, Vancouver - vancouver.bc.ca.undernet.org 
Europe, Netherlands, Amsterdam - amsterdam.nl.eu.undernet.org 
Europe, Netherlands, Diemen - diemen.nl.eu.undernet.org 
Europe, UK, London - london.uk.eu.undernet.org 
Europe, Sweden, Lulea - lulea.se.eu.undernet.org 
New Zealand, Aukland - auckland.nz.undernet.org 
US, Arizona, Phoenix - phoenix.az.us.undernet.org 
US, California, SanDiego - sandiego.ca.us.undernet.org 
US, Georgia, Atlanta - atlanta.ga.us.undernet.org 
US, Illinois, Chicago - chicago.il.us.Undernet.org 
US, Kansas, Manhattan - manhattan.ks.us.undernet.org 
US, Massachussetts, Lowell - lowell.ma.us.undernet.org 
US, Michigan, Ann Arbor - ann-arbor.mi.us.undernet.org 
US, Missouri, Springfield - springfield.mo.us.undernet.org 
US, Missouri, St.Louis - stlouis.mo.us.undernet.org 
US, Pennsylvania , Pittsburg - pittsburgh.pa.us.undernet.org 
US, Texas, Dallas - dallas.tx.us.undernet.org 
US, Virginia, Blacksburg - blacksburg.va.us.undernet.org 
US, Washington, Washington - washington.dc.us.undernet.org 

Undernet IRC Servers http://servers.undernet.org/

IRC-Net - IRC-Net is an IRC network that split of the large EFnet. It mainly consists of European servers but overseas servers might join later to make a new world-wide network. IRC-Net servers mainly use port 6667. 

Europe, Austria, Vienna - irc.wu-wien.ac.at 
Europe, Finland, Espoo - irc.funet.fi 
Europe, Finland, Kuopio - irc.pspt.fi 
Europe, France, Lyon - irc.univ-lyon1.fr 
Europe, Iceland, Reykjavik - irc.isnet.is 
Europe, Italy, Pisa - irc.ccii.unipi.it 
Europe, Netherlands, Nijmegen - irc.sci.kun.nl 
Europe, Netherlands, Amsterdam - irc.xs4all.nl 
Europe, Sweden, Lulea - irc.ludd.luth.se 
Europe, UK, London (PI) - london.uk.pi.net 
Europe, UK, London (Demon) - irc.demon.co.uk 
Europe, UK, London (Netcom) - irc.netcom.net.uk 
Europe, UK, London (BT) - chat.btinternet.com 
US, Chicago, Illinois - irc.igcom.net 

IRCnet IRC Servers http://w4u.eexi.gr/~shadow/.../ircnet.html
More IRCnet Servers http://www.ludd.luth.se/irc/servers.html
More IRCnet Servers http://www.irchelp.org/irchelp/networks/servers/ircnet.html

NewNet - NewNet is a new IRC network with currently 50+ servers linked. Its amount of users is still small but that might be just what you're looking for ? NewNet servers use port 6667. 

Africa, Zaire - irc.sprintlink.co.za 
US, Missouri, St. Louis -irc.primary.net 
US, Washington, Seattle - irc.eskimo.com 

Newnet IRC Servers http://www.newnet.net/servers.html

Brasilnet, BrasIRC and BrasNET - BrasIRC and BrasNET form the large Brazilian IRC Networks. They are dedicated to serve IRC users in and around Brazil and all people speaking Portuguese. These IRC servers use port 6667. 

ChatNet - ChatNet is another US based IRC network. ChatNet servers use port 6667. 

US, CA, Los Angeles - LosAngeles.CA.US.ChatNet.Org 
US, CA, San Francisco - SF.CA.US.Chatnet.Org 
US, CA, Walnut Creek - WalnutCreek.CA.US.ChatNet.Org 
US, FL, Pensacola - Pensacola.FL.US.ChatNet.Org 
US, ID, Pocatello - Pocatello.IS.US.ChatNet.Org 
US, KY, Louisville - Louisville.KY.US.ChatNet.Org 
US, MS, Tupelo - Tupelo.MS.US.Chatnet.Org 
US, OK, Stillwater - Stillwater.OK.US.ChatNet.Org 
US, OR, Portland - Portland.OR.US.Chatnet.Org 
US, SC, Rock Hill - RockHill.SC.US.ChatNet.Org 
US, UT, Salt Lake City - SLC.UT.US.Chatnet.Org 

ChatNet IRC Servers http://www.chatnet.org/htm/servers/list.htm

Starlink - Starlink is dedicated to provide an IRC experience that is friendly, comfortable, and pleasant for all who visit. Starlink servers use port 6667. 

Australia, Waverly - glen.vc.au.starlink.org 
US, Ohio, Cincinnati - cinci.oh.us.starlink.org 
US, Columbia, Aspen - aspen.co.us.starlink.org 
US, Michigan, Rochester - rochester.mi.us.starlink.org 

Galaxy Net - Galaxy Net is another small new IRC network. Its servers use port 6667. 

US, Atlanta - atlanta.ga.us.galaxynet.org 
US, Chicago - chicago.il.us.galaxynet.org 
US, Elpaso - elpaso.tx.us.galaxynet.org 
US, Fresno - fresno.ca.us.galaxynet.org 
US, Halifax - halifax.ns.ca.galaxynet.org 

Austnet - Austnet is a very well organised net of Australian origine. Austnet servers use port 6667. 

Asia, Singapore - ntu.sg.austnet.org 
Australia, Melbourne - aussie.au.austnet.org 
Australia, Sydney - sydney.au.austnet.org 
Canada, Toronto - insane.ca.austnet.org 
US, CA, Santa Clara - webmaster.us.AUSTnet.org 
US, FL, Wizard - wizard.us.austnet.org 
US, PA, Wallaby - wallaby.us.austnet.org 

More Networks.

 The list above is far from complete. There are lots and lots of IRC Networks and most of them have servers on all continents. Most networks have Web pages providing more information and up-to-date server lists. Have fun browsing around! 

Apatrix' list of servers. 
More IRC Servers http://www.irchelp.org/irchelp/networks/servers/
IRC specially for kids http://www.kidlink.org/IRC/