![[LISTSERV - the mailing list management classic]](https://www.lsoft.com/images/HDR-LISTSERV-sm.gif)
There are many possible ways to measure the relative "importance" or "size" of LISTSERV sites: number of lists, number of subscribers, number of messages delivered, etc. In most cases, the number of messages delivered is used to rank mailing list managers, because it is the most accurate measurement of the amount of activity on the server. But, depending on what you are looking for, other variables may be more appropriate. There are currently three LISTSERV "Top 20" lists, ranking the various servers according to:
In addition, you can view a list of the Top 20 lists in the network (by number of subscribers).
The statistics are gathered daily by a monitor at L-Soft which polls all the LISTSERV sites that participate in the "open" LISTSERV network over the worldwide Internet. Corporate servers operating in a "closed" environment are not included.
The statistics are organized in monthly reports. The message volume figures are a flat average of the accumulated traffic for the entire month. Thus, a server that delivers 300,000 messages per month will show a daily average of 10,000 messages. In practice, there is a lot less traffic during the weekend, and even during business days there can be significant fluctuations (~30%). The list statistics (number of lists, number of subscribers, largest lists in the network) are measured as of the last day in the month.
For the current month, the message volume figures are averaged based on the number of days that have elapsed. In practice, the figures are not very meaningful in the first few days, especially if the month starts on a weekend. In that case it is best to refer to the previous month for more accurate figures.
A fourth "Top 20" list is available for the more technically oriented: Number of messages generated by the server. This corresponds to the number of mail messages created by the server while processing postings to its mailing lists. LISTSERV delivers its mail using an intelligent mail delivery function called DISTRIBUTE, which improves mail delivery times and reduces bandwidth usage by spreading the delivery chore over scores of participating servers. Each of these servers processes the recipients for its service area (typically its organization or campus). In most cases, DISTRIBUTE simply alters the manner in which the mail is delivered, and the number of messages forwarded to other sites for optimized delivery is roughly equal to the number of messages received by other sites for the same purpose. In some cases, however, this is not the case, either because the server elected to serve a much wider service area than its own organization, or because it is explicitly forwarding all its deliveries to another machine (for instance, many mainframe-based servers forward their mail to a workstation or PC for delivery).
Pos Recipients Site --- ---------- ---- 1 937536 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 837120 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 435132 LISTS.PSU.EDU (AIX 6.1) 4 321599 LISTSERV.TAMU.EDU (Linux 3.0.101) 5 309203 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 295042 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 7 265626 LISTS.UFL.EDU (Linux 2.6.32) 8 259353 LISTSERV.UGA.EDU (Linux 2.6.32) 9 255768 LISTS.HAWAII.EDU (Linux 2.6.32-754.27.1.el6.x86_64) 10 250444 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 11 248771 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 12 238549 LISTES.ULAVAL.CA (Linux 3.10.0) 13 231960 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 14 219279 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 219073 LISTSERV.UA.EDU (Linux 4.12.14) 16 218986 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 17 215904 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 18 207807 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 19 182257 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 20 181445 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 4851433 LISTS.PSU.EDU (AIX 6.1) 2 4020187 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2255468 LS.KULEUVEN.BE (Linux 2.6.32) 4 1559129 LISTSERV.UGA.EDU (Linux 2.6.32) 5 1443925 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1255441 LISTSERV.UTORONTO.CA (Linux 3.10.0) 7 1228538 LISTS.WAYNE.EDU (Linux 2.6.32) 8 1224701 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 1090304 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1086952 LIST.MSU.EDU (Linux 3.10.0) 11 1076987 LISTS.UMN.EDU (Linux 3.10.0) 12 1059036 LISTS.UFL.EDU (Linux 2.6.32) 13 865216 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 852708 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 840739 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 16 838507 LISTSERV.UA.EDU (Linux 4.12.14) 17 819861 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 793386 LISTSERV.UH.EDU (Linux 3.10.0) 19 749189 LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 20 688371 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
Pos Lists Site --- ----- ---- 1 27793 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16573 LISTS.PSU.EDU (AIX 6.1) 3 13666 LISTSERV.TAU.AC.IL (Linux 2.6.9) 4 9788 LISTS.CLEMSON.EDU (Linux 2.6.18) 5 9599 LISTS.UFL.EDU (Linux 2.6.32) 6 8079 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 7 7291 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 6714 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6203 LISTSERV.UGA.EDU (Linux 2.6.32) 10 5610 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 5585 LISTS.UMN.EDU (Linux 3.10.0) 12 5235 LISTSERV.UTORONTO.CA (Linux 3.10.0) 13 5038 LISTSERV.TAMU.EDU (Linux 3.0.101) 14 4979 LS.KULEUVEN.BE (Linux 2.6.32) 15 4178 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 4091 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 4013 LISTS.QUEENSU.CA (Linux 3.10.0) 18 4009 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 19 3609 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 3298 LIST.UVM.EDU (Linux 2.6.32)
Pos Recipients Site --- ---------- ---- 1 908337 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 835441 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 430776 LISTS.PSU.EDU (AIX 6.1) 4 320834 LISTSERV.TAMU.EDU (Linux 3.0.101) 5 300909 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 262325 LISTS.UFL.EDU (Linux 2.6.32) 7 255084 LISTSERV.UGA.EDU (Linux 2.6.32) 8 253971 LISTS.HAWAII.EDU (Linux 2.6.32-754.27.1.el6.x86_64) 9 250196 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 10 245823 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 238366 LISTES.ULAVAL.CA (Linux 3.10.0) 12 231492 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 13 218735 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 14 214693 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 15 214362 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 214123 LISTSERV.UA.EDU (Linux 4.12.14) 17 207475 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 179992 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 19 176252 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 170720 LISTSERV.UTORONTO.CA (Linux 3.10.0)
Pos Subscribers Site --- ----------- ---- 1 59370 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 52360 ECF-EDNY@NYED.USCOURTS.GOV (Linux 3.10.0) 4 44151 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 41794 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 6 36461 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 8 33596 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 9 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 10 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 11 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 12 28309 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 13 28154 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 27709 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 15 27399 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 16 26419 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25009 2019-STEM-EVENT-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition) 18 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 19 24690 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 20 24436 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)