![[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 881036 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 488229 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 460718 LISTSERV.LIV.AC.UK (Linux 3.10.0) 4 375185 LISTS.PSU.EDU (Linux 3.10.0) 5 251201 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.49.1.el7.x86_64) 6 250446 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 7 246492 LISTES.ULAVAL.CA (Linux 3.10.0) 8 220444 LISTS.HAWAII.EDU (Linux 3.10.0-1160.59.1.el7.x86_64) 9 210815 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 10 205402 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 11 204370 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 12 199617 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 13 190882 LISTS.UFL.EDU (Linux 2.6.32) 14 181235 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 159404 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 146325 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 17 138976 LISTSERV.UTORONTO.CA (Linux 3.10.0) 18 132941 LISTSERV.UA.EDU (Linux 4.12.14) 19 132482 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 128910 LIST.UNM.EDU (Linux 3.10.0-1160.53.1.el7.x86_64)
Pos Subscribers Site --- ----------- ---- 1 5243270 LISTS.PSU.EDU (Linux 3.10.0) 2 5159707 LISTES.ULAVAL.CA (Linux 3.10.0) 3 1779137 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1387622 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1233162 LISTSERV.TAMU.EDU (Linux 3.0.101) 7 1200306 LISTSERV.UA.EDU (Linux 4.12.14) 8 1059036 LISTS.UFL.EDU (Linux 2.6.32) 9 1056546 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 1017943 LISTS.WAYNE.EDU (Linux 2.6.32) 11 1012129 LIST.MSU.EDU (Linux 3.10.0) 12 932463 LISTS.UMN.EDU (Linux 3.10.0) 13 865224 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 849892 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 16 842163 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 841670 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 825867 LISTSERV.UH.EDU (Linux 3.10.0) 19 710349 LISTSERV.LIV.AC.UK (Linux 3.10.0) 20 686456 LISTS.QUEENSU.CA (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 30860 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16599 LISTS.PSU.EDU (Linux 3.10.0) 3 14174 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 7193 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6763 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6266 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5251 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4988 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4813 LISTS.UMN.EDU (Linux 3.10.0) 13 4433 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4286 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3840 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 3808 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3465 LISTSERV.BROWN.EDU (Linux 3.10.0) 18 3415 LIST.UVM.EDU (Linux 2.6.32) 19 3282 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2784 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 847501 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 487290 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 451375 LISTSERV.LIV.AC.UK (Linux 3.10.0) 4 371998 LISTS.PSU.EDU (Linux 3.10.0) 5 250958 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.49.1.el7.x86_64) 6 246265 LISTES.ULAVAL.CA (Linux 3.10.0) 7 217737 LISTS.HAWAII.EDU (Linux 3.10.0-1160.59.1.el7.x86_64) 8 205212 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 9 200564 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 10 199359 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 11 188693 LISTS.UFL.EDU (Linux 2.6.32) 12 179053 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 13 165565 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 155969 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 15 144079 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 16 139164 LISTSERV.UTORONTO.CA (Linux 3.10.0) 17 129862 LISTSERV.UA.EDU (Linux 4.12.14) 18 128708 LIST.UNM.EDU (Linux 3.10.0-1160.53.1.el7.x86_64) 19 128218 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 110278 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 42126 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 3 41820 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 4 39337 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33114 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 8 30213 UG2021FALL@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 28887 TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 10 28269 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 11 27705 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 12 27587 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 13 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 14 27376 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 15 27347 UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0) 16 26421 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25030 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0) 18 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 19 24288 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 23186 L-AGSCINEWS@LISTS.PSU.EDU (Linux 3.10.0)