![[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 590454 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 368029 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 316341 LISTS.PSU.EDU (AIX 6.1) 4 226488 DISCUSSIONS.EQ.EDU.AU (Linux 2.6.18-404.el5) 5 219330 DIGITAL.ANNEXBUSINESSMEDIA.COM (Linux 3.13.0-32-generic) 6 218526 LIST.UNM.EDU (Linux 2.6.32-754.12.1.el6.x86_64) 7 218087 LISTSERV.UGA.EDU (Linux 2.6.32) 8 216870 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 9 180580 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 10 173296 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 166189 LISTSERV.LIV.AC.UK (Linux 2.6.32) 12 165376 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 13 165289 LISTS.UFL.EDU (Linux 2.6.32) 14 153513 LISTS.HAWAII.EDU (Linux 2.6.32-754.17.1.el6.x86_64) 15 150172 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 144467 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 17 132581 LISTSERV.UA.EDU (Linux 3.0.101) 18 127720 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 19 121737 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 120291 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
Pos Subscribers Site --- ----------- ---- 1 5120124 LISTS.PSU.EDU (AIX 6.1) 2 4667225 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2200120 LS.KULEUVEN.BE (Linux 2.6.32) 4 1470379 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1398082 LISTSERV.UGA.EDU (Linux 2.6.32) 6 1375420 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 7 1312840 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1282581 LISTSERV.UTORONTO.CA (Linux 3.10.0) 9 1245135 LISTS.WAYNE.EDU (Linux 2.6.32) 10 1059036 LISTS.UFL.EDU (Linux 2.6.32) 11 982099 LISTS.UMN.EDU (Linux 2.6.32) 12 944029 LIST.MSU.EDU (Linux 3.10.0) 13 850674 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 14 840938 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 15 834484 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 818258 CUVMC.AIS.COLUMBIA.EDU (VM/SP 4.0) 17 813154 LISTSERV.UA.EDU (Linux 3.0.101) 18 787366 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 787289 LISTSERV.UH.EDU (Linux 3.10.0) 20 771193 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Lists Site --- ----- ---- 1 34217 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16639 LISTS.PSU.EDU (AIX 6.1) 3 14042 LISTSERV.TAU.AC.IL (Linux 2.6.9) 4 11562 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 9788 LISTS.CLEMSON.EDU (Linux 2.6.18) 6 9599 LISTS.UFL.EDU (Linux 2.6.32) 7 8079 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 8 7708 MARIST (VM/SP 2.0) 9 7076 LISTSERV.LIV.AC.UK (Linux 2.6.32) 10 6686 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 11 5959 LISTSERV.UGA.EDU (Linux 2.6.32) 12 5467 LISTS.UMN.EDU (Linux 2.6.32) 13 5064 LISTSERV.TAMU.EDU (Linux 3.0.101) 14 4624 LS.KULEUVEN.BE (Linux 2.6.32) 15 4372 LISTSERV.UTORONTO.CA (Linux 3.10.0) 16 4276 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 3998 LISTS.QUEENSU.CA (Linux 3.10.0) 18 3986 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 3896 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 20 3507 LISTSERV.BUFFALO.EDU (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 565354 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 366943 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 311580 LISTS.PSU.EDU (AIX 6.1) 4 226286 DISCUSSIONS.EQ.EDU.AU (Linux 2.6.18-404.el5) 5 218315 LIST.UNM.EDU (Linux 2.6.32-754.12.1.el6.x86_64) 6 216387 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 7 212898 LISTSERV.UGA.EDU (Linux 2.6.32) 8 176357 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 9 170659 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 164038 LISTS.UFL.EDU (Linux 2.6.32) 11 159913 LISTSERV.LIV.AC.UK (Linux 2.6.32) 12 152491 LISTS.HAWAII.EDU (Linux 2.6.32-754.17.1.el6.x86_64) 13 144302 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 14 127790 LISTSERV.UA.EDU (Linux 3.0.101) 15 125466 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 16 120052 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 17 119265 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 118437 LISTES.ULAVAL.CA (Linux 3.10.0) 19 116687 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 20 115136 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 300656 COMPUTING@LIST.MSU.EDU (Linux 3.10.0) 2 61536 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 3 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 4 42899 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 41763 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 6 36545 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 8 33602 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 9 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 10 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 11 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 12 28314 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 13 28122 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 27709 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 15 27399 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 16 26419 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25008 2019-STEM-EVENT-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition) 18 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 19 24766 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 20 24483 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)