![[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 727866 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 420488 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 399875 LISTS.PSU.EDU (Linux 3.10.0) 4 303134 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 5 252128 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 6 233586 LISTES.ULAVAL.CA (Linux 3.10.0) 7 223295 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 8 222854 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 9 216982 LIST.UNM.EDU (Linux 3.10.0-1160.53.1.el7.x86_64) 10 208446 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 205585 LISTS.HAWAII.EDU (Linux 3.10.0-1160.62.1.el7.x86_64) 12 197831 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 13 171741 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 14 158410 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 15 158270 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 16 157106 LISTS.UFL.EDU (Linux 2.6.32) 17 143947 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 128365 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 19 122190 LISTSERV.TDBANK.CA (Windows Server 2016 Datacenter x64 Edition) 20 106741 LISTS.WAYNE.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 5226609 LISTS.PSU.EDU (Linux 3.10.0) 2 5204162 LISTES.ULAVAL.CA (Linux 3.10.0) 3 1886740 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1398876 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1232804 LISTSERV.UA.EDU (Linux 4.12.14) 7 1227914 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1059036 LISTS.UFL.EDU (Linux 2.6.32) 9 1054853 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 1047630 LISTS.WAYNE.EDU (Linux 2.6.32) 11 1019043 LIST.MSU.EDU (Linux 3.10.0) 12 933546 LISTS.UMN.EDU (Linux 3.10.0) 13 867372 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 845514 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 844649 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 829748 LISTSERV.UH.EDU (Linux 3.10.0) 18 789453 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 19 690161 LISTS.QUEENSU.CA (Linux 3.10.0) 20 688917 LISTSERV.LIV.AC.UK (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 31648 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 6765 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6300 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5272 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4988 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 4301 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 3475 LISTSERV.BROWN.EDU (Linux 3.10.0) 18 3420 LIST.UVM.EDU (Linux 2.6.32) 19 3287 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2785 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 697464 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 411894 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 396705 LISTS.PSU.EDU (Linux 3.10.0) 4 302718 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 5 233389 LISTES.ULAVAL.CA (Linux 3.10.0) 6 222636 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 7 216800 LIST.UNM.EDU (Linux 3.10.0-1160.53.1.el7.x86_64) 8 204680 LISTS.HAWAII.EDU (Linux 3.10.0-1160.62.1.el7.x86_64) 9 204590 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 10 197237 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 11 168451 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 12 168230 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 13 156140 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 14 156014 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 155352 LISTS.UFL.EDU (Linux 2.6.32) 16 139254 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 17 126231 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 18 103470 LISTSERV.UTORONTO.CA (Linux 3.10.0) 19 100064 LIST.UVM.EDU (Linux 2.6.32) 20 98619 LISTS.WAYNE.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 42296 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 3 41821 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 4 39329 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 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 27713 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 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 25030 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 23041 L-AGSCINEWS@LISTS.PSU.EDU (Linux 3.10.0)