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 1175704 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 2 845157 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 3 433883 LISTSERV.TAMU.EDU (Linux 3.0.101) 4 353555 LISTS.PSU.EDU (AIX 6.1) 5 346786 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 224245 LISTES.ULAVAL.CA (Linux 3.10.0) 7 215095 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1127.19.1.el7.x86_64) 8 209778 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 9 208358 LISTS.UFL.EDU (Linux 2.6.32) 10 197857 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 11 196013 LISTS.HAWAII.EDU (Linux 2.6.32-754.35.1.el6.x86_64) 12 191919 LISTSERV.UGA.EDU (Linux 2.6.32) 13 184607 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 14 174062 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 15 162825 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 16 160207 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 17 148226 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 18 147750 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 19 131316 MASSMAIL.VCU.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 20 119370 LISTSERV.UTORONTO.CA (Linux 3.10.0)
Pos Subscribers Site --- ----------- ---- 1 5188324 LISTES.ULAVAL.CA (Linux 3.10.0) 2 4932919 LISTS.PSU.EDU (AIX 6.1) 3 2229985 LS.KULEUVEN.BE (Linux 2.6.32) 4 1539210 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1413427 LISTSERV.UGA.EDU (Linux 2.6.32) 6 1316066 LISTS.WAYNE.EDU (Linux 2.6.32) 7 1217494 LISTSERV.UTORONTO.CA (Linux 3.10.0) 8 1198891 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 1134416 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1101188 LIST.MSU.EDU (Linux 3.10.0) 11 1059036 LISTS.UFL.EDU (Linux 2.6.32) 12 962416 LISTS.UMN.EDU (Linux 3.10.0) 13 937525 LISTSERV.UA.EDU (Linux 4.12.14) 14 888789 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 850165 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 848556 LISTSERV.UH.EDU (Linux 3.10.0) 17 843240 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 18 814461 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 19 801100 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 750280 LISTS.MAINE.EDU (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 34750 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16990 LISTS.PSU.EDU (AIX 6.1) 3 11416 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 7498 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 6733 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 5750 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 5482 LISTSERV.UTORONTO.CA (Linux 3.10.0) 11 5221 LS.KULEUVEN.BE (Linux 2.6.32) 12 5024 LISTSERV.TAMU.EDU (Linux 3.0.101) 13 4917 LISTS.UMN.EDU (Linux 3.10.0) 14 4839 LISTSERV.UGA.EDU (Linux 2.6.32) 15 4211 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 4164 LISTS.QUEENSU.CA (Linux 3.10.0) 17 4046 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 18 3839 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 19 3692 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 3334 LISTSERV.BROWN.EDU (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 1173769 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 2 814712 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 3 433256 LISTSERV.TAMU.EDU (Linux 3.0.101) 4 350647 LISTS.PSU.EDU (AIX 6.1) 5 336806 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 224051 LISTES.ULAVAL.CA (Linux 3.10.0) 7 214875 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1127.19.1.el7.x86_64) 8 206475 LISTS.UFL.EDU (Linux 2.6.32) 9 195642 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 10 194521 LISTS.HAWAII.EDU (Linux 2.6.32-754.35.1.el6.x86_64) 11 188262 LISTSERV.UGA.EDU (Linux 2.6.32) 12 176943 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 13 173135 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 14 162624 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 15 148622 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 145960 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 17 143618 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 119372 LISTSERV.UTORONTO.CA (Linux 3.10.0) 19 111557 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 20 107193 LISTSERV.UA.EDU (Linux 4.12.14)
Pos Subscribers Site --- ----------- ---- 1 59287 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 43546 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 4 41804 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 5 36126 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 6 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 7 33583 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 8 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 9 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 10 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 11 28305 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 12 27708 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 13 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 14 27390 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 15 27352 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 16 26418 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25574 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 18 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 19 24317 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 23332 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0)