![[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 722834 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 248554 LISTS.PSU.EDU (AIX 6.1) 3 230000 DIGITAL.ANNEXBUSINESSMEDIA.COM (Linux 3.13.0-32-generic) 4 218438 LISTSERV.LIV.AC.UK (Linux 2.6.32) 5 189551 DISCUSSIONS.EQ.EDU.AU (Linux 2.6.18-404.el5) 6 184050 LISTSERV.BUFFALO.EDU (Solaris 2.11) 7 178440 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 8 172547 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 9 167079 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 10 163626 LISTSERV.TAMU.EDU (Linux 3.0.101) 11 150888 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 12 138511 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 13 134496 LISTSERV.UGA.EDU (Linux 2.6.32) 14 132452 LISTSERV.UA.EDU (Linux 3.0.101) 15 126642 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 16 126239 LISTS.UCDENVER.EDU (Windows Server 2012 R2 Standard x64 Edition) 17 119836 LISTSERV.UMD.EDU (SunOS 5.10) 18 115856 LISTSERV.DARTMOUTH.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 115353 LISTS.HAWAII.EDU (Linux 2.6.32-696.20.1.el6.x86_64) 20 110996 LISTS.UFL.EDU (Linux 2.6.18)
Pos Subscribers Site --- ----------- ---- 1 5261662 LISTS.PSU.EDU (AIX 6.1) 2 3541788 LISTES.ULAVAL.CA (Linux 2.6.18) 3 2083267 LS.KULEUVEN.BE (Linux 2.6.32) 4 1567446 LISTS.WAYNE.EDU (Linux 2.6.32) 5 1423903 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 6 1367926 LISTSERV.TAU.AC.IL (Linux 2.6.9) 7 1367683 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1321761 LISTSERV.UGA.EDU (Linux 2.6.32) 9 1282581 LISTSERV.UTORONTO.CA (Linux 2.6.18) 10 1059036 LISTS.UFL.EDU (Linux 2.6.18) 11 1027084 LISTSERV.BUFFALO.EDU (Solaris 2.11) 12 1008828 LISTS.UMN.EDU (Linux 2.6.32) 13 944029 LIST.MSU.EDU (Linux 3.10.0) 14 878904 LISTSERV.UH.EDU (Linux 3.10.0) 15 818258 CUVMC.AIS.COLUMBIA.EDU (VM/SP 4.0) 16 791683 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 761633 LISTSERV.UA.EDU (Linux 3.0.101) 18 740792 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 685267 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 678876 LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Lists Site --- ----- ---- 1 27297 LISTES.ULAVAL.CA (Linux 2.6.18) 2 16707 LISTS.PSU.EDU (AIX 6.1) 3 14132 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 4 13665 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 8177 LISTSERV.UH.EDU (Linux 3.10.0) 8 8053 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 9 7301 MARIST (VM/SP 2.0) 10 6847 LISTSERV.TAMU.EDU (Linux 3.0.101) 11 6589 LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition) 12 6491 LISTSERV.LIV.AC.UK (Linux 2.6.32) 13 5720 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 14 5501 LISTS.UMN.EDU (Linux 2.6.32) 15 5382 LISTSERV.UGA.EDU (Linux 2.6.32) 16 4430 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 4372 LISTSERV.UTORONTO.CA (Linux 2.6.18) 18 4267 LS.KULEUVEN.BE (Linux 2.6.32) 19 3838 LISTS.QUEENSU.CA (Solaris 2.10) 20 3809 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Recipients Site --- ---------- ---- 1 695629 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 243455 LISTS.PSU.EDU (AIX 6.1) 3 207583 LISTSERV.LIV.AC.UK (Linux 2.6.32) 4 189343 DISCUSSIONS.EQ.EDU.AU (Linux 2.6.18-404.el5) 5 179472 LISTSERV.BUFFALO.EDU (Solaris 2.11) 6 171966 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 7 164182 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 8 162641 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 147667 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 10 130919 LISTSERV.UGA.EDU (Linux 2.6.32) 11 127366 LISTSERV.UA.EDU (Linux 3.0.101) 12 126214 LISTS.UCDENVER.EDU (Windows Server 2012 R2 Standard x64 Edition) 13 124110 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 14 119681 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 114035 LISTS.HAWAII.EDU (Linux 2.6.32-696.20.1.el6.x86_64) 16 110785 LISTSERV.DARTMOUTH.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 109154 LISTS.UFL.EDU (Linux 2.6.18) 18 108131 LIST.UVM.EDU (Linux 2.6.32) 19 107734 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 20 104247 LISTSERV.UMD.EDU (SunOS 5.10)
Pos Subscribers Site --- ----------- ---- 1 300656 COMPUTING@LIST.MSU.EDU (Linux 3.10.0) 2 62422 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 3 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 4 41760 OPSWNEWS@LISTSERV.NYSED.GOV (AIX 7.1) 5 38731 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 6 35713 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 8 33781 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 9 33608 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 28662 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 28336 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 27080 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 24866 ISMA@LS.KULEUVEN.BE (Linux 2.6.32)