![[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 832580 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 618308 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 405842 LISTSERV.LIV.AC.UK (Linux 3.10.0) 4 286349 LISTS.PSU.EDU (Linux 3.10.0) 5 220407 LISTSERV.TAMU.EDU (Linux 3.0.101) 6 208532 LIST.UNM.EDU (Linux 3.10.0-1160.25.1.el7.x86_64) 7 204596 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 8 201865 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.21.1.el7.x86_64) 9 197578 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 10 178914 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 11 172218 LISTES.ULAVAL.CA (Linux 3.10.0) 12 152965 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 13 149510 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 14 149422 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 15 133498 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 131212 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 17 124588 LISTS.UFL.EDU (Linux 2.6.32) 18 120248 MASSMAIL.VCU.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 19 119796 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 20 113383 LIST.UVM.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 4923594 LISTS.PSU.EDU (Linux 3.10.0) 2 4493917 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2312293 LS.KULEUVEN.BE (Linux 2.6.32) 4 1766726 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1625669 LISTSERV.UGA.EDU (Linux 2.6.32) 6 1239306 LISTS.WAYNE.EDU (Linux 2.6.32) 7 1195395 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1158404 LISTSERV.UTORONTO.CA (Linux 3.10.0) 9 1130208 LISTSERV.UA.EDU (Linux 4.12.14) 10 1071739 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 11 1059036 LISTS.UFL.EDU (Linux 2.6.32) 12 934936 LISTS.UMN.EDU (Linux 3.10.0) 13 854673 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 829325 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 826997 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 824397 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 17 793445 LISTSERV.UH.EDU (Linux 3.10.0) 18 752987 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 19 694320 LISTSERV.LIV.AC.UK (Linux 3.10.0) 20 670120 LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
Pos Lists Site --- ----- ---- 1 27783 LISTES.ULAVAL.CA (Linux 3.10.0) 2 17075 LISTS.PSU.EDU (Linux 3.10.0) 3 14167 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 7595 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6742 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 5800 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5384 LS.KULEUVEN.BE (Linux 2.6.32) 11 5001 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4959 LISTSERV.UGA.EDU (Linux 2.6.32) 13 4872 LISTS.UMN.EDU (Linux 3.10.0) 14 4512 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 4305 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 4235 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3794 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 3582 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 19 3367 LIST.UVM.EDU (Linux 2.6.32) 20 3345 LISTSERV.BROWN.EDU (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 800549 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 617198 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 397540 LISTSERV.LIV.AC.UK (Linux 3.10.0) 4 282883 LISTS.PSU.EDU (Linux 3.10.0) 5 216198 LISTSERV.TAMU.EDU (Linux 3.0.101) 6 208320 LIST.UNM.EDU (Linux 3.10.0-1160.25.1.el7.x86_64) 7 201670 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.21.1.el7.x86_64) 8 176681 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 9 171974 LISTES.ULAVAL.CA (Linux 3.10.0) 10 150899 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 11 147459 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 12 146593 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 13 134993 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 131013 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 15 129206 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 123098 LISTS.UFL.EDU (Linux 2.6.32) 17 119596 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 18 111927 LIST.UVM.EDU (Linux 2.6.32) 19 109744 LISTSERV.UA.EDU (Linux 4.12.14) 20 98742 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 59226 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 41812 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 4 39934 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33996 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 33558 L-SMEAL-REPORT@LISTS.PSU.EDU (Linux 3.10.0) 8 32013 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 9 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 10 29093 TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 11 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 12 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 13 28295 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 14 28089 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 15 27707 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 16 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 17 27390 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 18 26419 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 19 25562 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 20 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0)