![[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 645319 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 265252 LISTS.PSU.EDU (AIX 6.1) 3 186738 DIGITAL.ANNEXBUSINESSMEDIA.COM (Linux 3.13.0-32-generic) 4 177655 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 5 176234 LISTSERV.TAMU.EDU (Linux 3.0.101) 6 174812 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 7 171402 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 164533 LISTSERV.BUFFALO.EDU (Solaris 2.11) 9 143221 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 10 140731 LISTSERV.UGA.EDU (Linux 2.6.32) 11 134593 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 12 125577 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 13 124410 LISTSERV.UA.EDU (Linux 3.0.101) 14 124104 LISTSERV.DARTMOUTH.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 115607 LISTS.UFL.EDU (Linux 2.6.18) 16 115578 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 17 114791 DISCUSSIONS.EQ.EDU.AU (Linux 2.6.18-404.el5) 18 113116 LISTS.HAWAII.EDU (Linux 2.6.32-696.23.1.el6.x86_64) 19 109910 LIST.UVM.EDU (Linux 2.6.32) 20 109657 LISTS.UCDENVER.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5273485 LISTS.PSU.EDU (AIX 6.1) 2 3535627 LISTES.ULAVAL.CA (Linux 2.6.18) 3 2115283 LS.KULEUVEN.BE (Linux 2.6.32) 4 1568143 LISTS.WAYNE.EDU (Linux 2.6.32) 5 1413807 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1392249 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 7 1350824 LISTSERV.UGA.EDU (Linux 2.6.32) 8 1327913 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 1282581 LISTSERV.UTORONTO.CA (Linux 2.6.18) 10 1059036 LISTS.UFL.EDU (Linux 2.6.18) 11 1035276 LISTSERV.BUFFALO.EDU (Solaris 2.11) 12 1007724 LISTS.UMN.EDU (Linux 2.6.32) 13 944029 LIST.MSU.EDU (Linux 3.10.0) 14 881785 LISTSERV.UH.EDU (Linux 3.10.0) 15 818258 CUVMC.AIS.COLUMBIA.EDU (VM/SP 4.0) 16 800588 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 752382 LISTSERV.UA.EDU (Linux 3.0.101) 18 738627 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 689558 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 683554 LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Lists Site --- ----- ---- 1 27318 LISTES.ULAVAL.CA (Linux 2.6.18) 2 16748 LISTS.PSU.EDU (AIX 6.1) 3 14151 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 4 13697 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 9788 LISTS.CLEMSON.EDU (Linux 2.6.18) 6 9599 LISTS.UFL.EDU (Linux 2.6.18) 7 8190 LISTSERV.UH.EDU (Linux 3.10.0) 8 8077 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 9 7410 MARIST (VM/SP 2.0) 10 6596 LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition) 11 6500 LISTSERV.LIV.AC.UK (Linux 2.6.32) 12 6184 LISTSERV.TAMU.EDU (Linux 3.0.101) 13 5721 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 14 5507 LISTS.UMN.EDU (Linux 2.6.32) 15 5406 LISTSERV.UGA.EDU (Linux 2.6.32) 16 4437 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 4372 LISTSERV.UTORONTO.CA (Linux 2.6.18) 18 4293 LS.KULEUVEN.BE (Linux 2.6.32) 19 3857 LISTS.QUEENSU.CA (Solaris 2.10) 20 3811 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Recipients Site --- ---------- ---- 1 620592 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 260482 LISTS.PSU.EDU (AIX 6.1) 3 175337 LISTSERV.TAMU.EDU (Linux 3.0.101) 4 175113 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 5 162716 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 160300 LISTSERV.BUFFALO.EDU (Solaris 2.11) 7 140664 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 8 136917 LISTSERV.UGA.EDU (Linux 2.6.32) 9 122975 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 119749 LISTSERV.DARTMOUTH.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 11 119745 LISTSERV.UA.EDU (Linux 3.0.101) 12 115363 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 13 114691 DISCUSSIONS.EQ.EDU.AU (Linux 2.6.18-404.el5) 14 113707 LISTS.UFL.EDU (Linux 2.6.18) 15 112410 LISTS.HAWAII.EDU (Linux 2.6.32-696.23.1.el6.x86_64) 16 109625 LISTS.UCDENVER.EDU (Windows Server 2012 R2 Standard x64 Edition) 17 108062 LIST.UVM.EDU (Linux 2.6.32) 18 105472 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 100753 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 20 97737 LISTS.UMN.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 300656 COMPUTING@LIST.MSU.EDU (Linux 3.10.0) 2 62412 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 3 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 4 41763 OPSWNEWS@LISTSERV.NYSED.GOV (AIX 7.1) 5 38963 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 6 38682 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 7 35712 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 8 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 9 33607 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 10 30836 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 11 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 12 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 13 28865 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 28332 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 15 27709 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition) 16 27408 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 17 27079 HINDU-D@LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 26418 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 19 24990 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 2.6.32) 20 24863 ISMA@LS.KULEUVEN.BE (Linux 2.6.32)