![[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 835399 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 384713 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 273963 LISTS.PSU.EDU (Linux 3.10.0) 4 228488 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 5 223620 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.24.1.el7.x86_64) 6 202935 LISTSERV.TAMU.EDU (Linux 3.0.101) 7 174939 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 8 144193 LISTS.HAWAII.EDU (Linux 3.10.0-1160.25.1.el7.x86_64) 9 141856 LISTES.ULAVAL.CA (Linux 3.10.0) 10 140944 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 11 123456 LISTS.UFL.EDU (Linux 2.6.32) 12 121410 LIST.UNM.EDU (Linux 3.10.0-1160.25.1.el7.x86_64) 13 114185 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 112097 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 15 107864 LISTS.ROCHESTER.EDU (Windows Server 2012 R2 Standard x64 Edition) 16 107799 LISTSERV.UA.EDU (Linux 4.12.14) 17 106912 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 18 106624 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 19 102115 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 102062 LISTSERV.BUFFALO.EDU (Linux 3.10.0)
Pos Subscribers Site --- ----------- ---- 1 4821082 LISTS.PSU.EDU (Linux 3.10.0) 2 4484498 LISTES.ULAVAL.CA (Linux 3.10.0) 3 1775555 LISTSERV.TAU.AC.IL (Linux 2.6.9) 4 1631516 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 1252213 LISTS.WAYNE.EDU (Linux 2.6.32) 6 1217465 LISTSERV.TAMU.EDU (Linux 3.0.101) 7 1166849 LISTSERV.UTORONTO.CA (Linux 3.10.0) 8 1059036 LISTS.UFL.EDU (Linux 2.6.32) 9 1027685 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 956620 LISTSERV.UA.EDU (Linux 4.12.14) 11 932231 LISTS.UMN.EDU (Linux 3.10.0) 12 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 13 828790 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 14 805016 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 15 786971 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 16 767806 LISTSERV.UH.EDU (Linux 3.10.0) 17 752615 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 18 688721 LISTSERV.LIV.AC.UK (Linux 3.10.0) 19 673942 LIST.MSU.EDU (Linux 3.10.0) 20 673676 LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
Pos Lists Site --- ----- ---- 1 27876 LISTES.ULAVAL.CA (Linux 3.10.0) 2 17144 LISTS.PSU.EDU (Linux 3.10.0) 3 14172 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 7598 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6744 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 5932 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5000 LISTSERV.TAMU.EDU (Linux 3.0.101) 11 4948 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 12 4877 LISTS.UMN.EDU (Linux 3.10.0) 13 4309 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4164 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3798 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 3697 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3589 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 18 3370 LIST.UVM.EDU (Linux 2.6.32) 19 3351 LISTSERV.BROWN.EDU (Linux 3.10.0) 20 2743 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 803919 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 376751 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 270432 LISTS.PSU.EDU (Linux 3.10.0) 4 223391 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.24.1.el7.x86_64) 5 198574 LISTSERV.TAMU.EDU (Linux 3.0.101) 6 174506 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 7 142756 LISTS.HAWAII.EDU (Linux 3.10.0-1160.25.1.el7.x86_64) 8 141529 LISTES.ULAVAL.CA (Linux 3.10.0) 9 140751 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 10 121710 LISTS.UFL.EDU (Linux 2.6.32) 11 121214 LIST.UNM.EDU (Linux 3.10.0-1160.25.1.el7.x86_64) 12 110094 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 13 106728 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 14 104755 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 104427 LISTSERV.UA.EDU (Linux 4.12.14) 16 100014 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 17 98147 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 97936 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 19 97222 LIST.MSU.EDU (Linux 3.10.0) 20 93855 LIST.UVM.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 59223 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 42868 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 4 41812 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33994 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 33551 L-SMEAL-REPORT@LISTS.PSU.EDU (Linux 3.10.0) 8 31743 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 9 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 10 28973 TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 11 28292 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 12 28142 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 13 27707 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 14 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 15 27383 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 16 27349 UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0) 17 26420 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 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 23331 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0)