![[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 575657 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 427767 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 350850 LISTS.PSU.EDU (Linux 3.10.0) 4 281658 LISTS.HAWAII.EDU (Linux 3.10.0-1160.62.1.el7.x86_64) 5 259148 LISTES.ULAVAL.CA (Linux 3.10.0) 6 206199 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 7 194596 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 8 188643 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 183274 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 10 176342 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 11 172492 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 12 171310 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 13 146056 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 14 143350 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 15 133925 LISTS.SENATE.GOV (Windows Server 2016 Standard x64 Edition) 16 131794 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 17 121998 LISTS.UFL.EDU (Linux 2.6.32) 18 116970 LISTSERV.HAMILTON.EDU (Windows Server 2012 R2 Standard x64 Edition) 19 112492 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 20 110288 MASSMAIL.VCU.EDU (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5207907 LISTES.ULAVAL.CA (Linux 3.10.0) 2 5205766 LISTS.PSU.EDU (Linux 3.10.0) 3 1878317 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1398251 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1233604 LISTSERV.UA.EDU (Linux 4.12.14) 7 1227754 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1062856 LISTS.WAYNE.EDU (Linux 2.6.32) 9 1059036 LISTS.UFL.EDU (Linux 2.6.32) 10 1054923 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 11 1018626 LIST.MSU.EDU (Linux 3.10.0) 12 933279 LISTS.UMN.EDU (Linux 3.10.0) 13 876037 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 852333 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 844933 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 831775 LISTSERV.UH.EDU (Linux 3.10.0) 18 789450 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 19 692399 LISTSERV.LIV.AC.UK (Linux 3.10.0) 20 690141 LISTS.QUEENSU.CA (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 31955 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16628 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 7145 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6766 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6303 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5276 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4987 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4819 LISTS.UMN.EDU (Linux 3.10.0) 13 4444 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4302 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3847 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 3820 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3480 LISTSERV.BROWN.EDU (Linux 3.10.0) 18 3421 LIST.UVM.EDU (Linux 2.6.32) 19 3290 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2787 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 544367 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 417732 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 347466 LISTS.PSU.EDU (Linux 3.10.0) 4 281179 LISTS.HAWAII.EDU (Linux 3.10.0-1160.62.1.el7.x86_64) 5 258994 LISTES.ULAVAL.CA (Linux 3.10.0) 6 206056 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 7 190454 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 8 184782 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 169845 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 168688 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 11 143202 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 12 142365 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 13 142195 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 14 133928 LISTS.SENATE.GOV (Windows Server 2016 Standard x64 Edition) 15 131672 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 16 121184 LISTS.UFL.EDU (Linux 2.6.32) 17 116909 LISTSERV.HAMILTON.EDU (Windows Server 2012 R2 Standard x64 Edition) 18 110255 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 19 103777 LIST.UVM.EDU (Linux 2.6.32) 20 103457 LISTSERV.TAU.AC.IL (Linux 2.6.9)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 41822 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 3 39328 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 37592 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33112 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 8 30209 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 28267 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 11 27705 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 12 27579 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 25029 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 23021 L-AGSCINEWS@LISTS.PSU.EDU (Linux 3.10.0)