![[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 715475 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 340582 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 328369 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 4 304436 LISTS.PSU.EDU (Linux 3.10.0) 5 252613 LISTES.ULAVAL.CA (Linux 3.10.0) 6 230089 LISTS.HAWAII.EDU (Linux 3.10.0-1160.49.1.el7.x86_64) 7 221129 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 8 197272 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 172374 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 10 164394 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 11 159635 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 12 157176 LISTS.UFL.EDU (Linux 2.6.32) 13 155343 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 14 148679 LISTSERV.TDBANK.CA (Windows Server 2016 Datacenter x64 Edition) 15 144070 LISTSERV.UA.EDU (Linux 4.12.14) 16 135678 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 17 135332 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 18 115791 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.45.1.el7.x86_64) 19 110916 LISTS.ROCHESTER.EDU (Windows Server 2012 R2 Standard x64 Edition) 20 109629 LISTSERV.ICORS.ORG (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5455394 LISTS.PSU.EDU (Linux 3.10.0) 2 4680343 LISTES.ULAVAL.CA (Linux 3.10.0) 3 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 4 1717320 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 1509167 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1258355 LISTSERV.TAMU.EDU (Linux 3.0.101) 7 1170761 LISTSERV.UA.EDU (Linux 4.12.14) 8 1059036 LISTS.UFL.EDU (Linux 2.6.32) 9 1032529 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 1030512 LISTS.WAYNE.EDU (Linux 2.6.32) 11 991722 LIST.MSU.EDU (Linux 3.10.0) 12 925632 LISTS.UMN.EDU (Linux 3.10.0) 13 863711 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 850760 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 837835 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 17 836531 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 18 814325 LISTSERV.UH.EDU (Linux 3.10.0) 19 700233 LISTSERV.LIV.AC.UK (Linux 3.10.0) 20 682510 LISTS.QUEENSU.CA (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 27906 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16535 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 7136 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6763 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6170 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5189 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4988 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4809 LISTS.UMN.EDU (Linux 3.10.0) 13 4422 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4237 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3819 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 3771 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3431 LISTSERV.BROWN.EDU (Linux 3.10.0) 18 3408 LIST.UVM.EDU (Linux 2.6.32) 19 3290 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2774 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 687153 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 332712 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 327887 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 4 301426 LISTS.PSU.EDU (Linux 3.10.0) 5 252423 LISTES.ULAVAL.CA (Linux 3.10.0) 6 227734 LISTS.HAWAII.EDU (Linux 3.10.0-1160.49.1.el7.x86_64) 7 193340 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 8 170469 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 9 164199 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 10 156087 LISTS.UFL.EDU (Linux 2.6.32) 11 152022 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 12 141100 LISTSERV.UA.EDU (Linux 4.12.14) 13 135471 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 14 133164 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 115725 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.45.1.el7.x86_64) 16 112638 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 17 108548 LISTSERV.UTORONTO.CA (Linux 3.10.0) 18 107925 LISTSERV.ICORS.ORG (Windows Server 2016 Datacenter x64 Edition) 19 103929 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 20 98435 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 41953 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 3 41816 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 4 39349 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33786 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 8 30223 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 28276 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 11 27706 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 27379 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 15 27348 UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0) 16 26421 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 18 24633 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0) 19 24288 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 22770 STUDENT-TRAVEL-SURVEY-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition)