![[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 639599 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 370916 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 240379 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 4 209500 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 5 191728 LISTS.PSU.EDU (Linux 3.10.0) 6 172723 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 7 136368 LISTES.ULAVAL.CA (Linux 3.10.0) 8 107530 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 106979 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 10 103103 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 11 99821 LISTS.UFL.EDU (Linux 2.6.32) 12 99106 LISTS.HAWAII.EDU (Linux 3.10.0-1160.62.1.el7.x86_64) 13 95395 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 14 94007 LISTSERV.BROWN.EDU (Linux 3.10.0) 15 90672 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 16 88601 LISTSERV.UA.EDU (Linux 4.12.14) 17 84548 LISTS.PORTSIDE.ORG (Linux 4.9.0-17-amd64) 18 84090 LISTSERV.UTORONTO.CA (Linux 3.10.0) 19 82427 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 81739 LISTSERV.TDBANK.CA (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5163795 LISTS.PSU.EDU (Linux 3.10.0) 2 4550279 LISTES.ULAVAL.CA (Linux 3.10.0) 3 1831005 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1246848 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1210167 LISTSERV.UA.EDU (Linux 4.12.14) 7 1172558 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1059036 LISTS.UFL.EDU (Linux 2.6.32) 9 1038574 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 986738 LISTS.WAYNE.EDU (Linux 2.6.32) 11 933521 LISTS.UMN.EDU (Linux 3.10.0) 12 905463 LIST.MSU.EDU (Linux 3.10.0) 13 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 825069 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 814914 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 16 792633 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 17 775261 LISTSERV.UH.EDU (Linux 3.10.0) 18 775094 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 19 701321 LISTS.QUEENSU.CA (Linux 3.10.0) 20 694000 LISTSERV.LIV.AC.UK (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 28155 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16622 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 7165 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6769 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6366 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5315 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4986 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4817 LISTS.UMN.EDU (Linux 3.10.0) 13 4456 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4265 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3850 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 3846 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3534 LIST.UVM.EDU (Linux 2.6.32) 18 3484 LISTSERV.BROWN.EDU (Linux 3.10.0) 19 3303 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2794 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 610945 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 362822 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 209298 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 4 188828 LISTS.PSU.EDU (Linux 3.10.0) 5 170637 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 6 136202 LISTES.ULAVAL.CA (Linux 3.10.0) 7 106820 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 8 105799 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 98731 LISTS.HAWAII.EDU (Linux 3.10.0-1160.62.1.el7.x86_64) 10 98294 LISTS.UFL.EDU (Linux 2.6.32) 11 95196 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 12 88746 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 13 87334 LISTSERV.BROWN.EDU (Linux 3.10.0) 14 86248 LISTSERV.UA.EDU (Linux 4.12.14) 15 84523 LISTS.PORTSIDE.ORG (Linux 4.9.0-17-amd64) 16 83931 LISTSERV.UTORONTO.CA (Linux 3.10.0) 17 82837 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 18 79796 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 19 79328 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 20 77179 LISTSERV.ICORS.ORG (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 43261 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 3 41822 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 4 39327 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33110 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 8 30207 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 28265 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 11 27982 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 12 27705 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 13 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 14 27375 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 15 27347 UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0) 16 26422 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25027 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 22830 L-AGSCINEWS@LISTS.PSU.EDU (Linux 3.10.0)