![[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 947804 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 2 847373 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 3 324313 LISTS.PSU.EDU (AIX 6.1) 4 229459 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 5 214222 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 191213 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 7 189934 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 8 166350 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 161470 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 10 159027 LISTS.UFL.EDU (Linux 2.6.32) 11 158826 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 12 157478 LISTSERV.UGA.EDU (Linux 2.6.32) 13 153859 LISTS.HAWAII.EDU (Linux 2.6.32-754.29.2.el6.x86_64) 14 149949 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 15 145867 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 145756 LISTSERV.UA.EDU (Linux 4.12.14) 17 140271 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 18 139274 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 19 132010 LISTES.ULAVAL.CA (Linux 3.10.0) 20 122272 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 4847976 LISTS.PSU.EDU (AIX 6.1) 2 4176506 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2286921 LS.KULEUVEN.BE (Linux 2.6.32) 4 1642476 LISTSERV.UGA.EDU (Linux 2.6.32) 5 1455765 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1229821 LISTS.WAYNE.EDU (Linux 2.6.32) 7 1208933 LISTSERV.UTORONTO.CA (Linux 3.10.0) 8 1208539 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 1087634 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1059036 LISTS.UFL.EDU (Linux 2.6.32) 11 1029106 LIST.MSU.EDU (Linux 3.10.0) 12 972445 LISTS.UMN.EDU (Linux 3.10.0) 13 854813 LISTSERV.UA.EDU (Linux 4.12.14) 14 838962 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 826059 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 814791 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 761803 LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 18 757457 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 19 747365 LISTSERV.UH.EDU (Linux 3.10.0) 20 721624 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Lists Site --- ----- ---- 1 27608 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16569 LISTS.PSU.EDU (AIX 6.1) 3 14042 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 7458 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 6722 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6269 LISTSERV.UGA.EDU (Linux 2.6.32) 10 5643 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 5382 LISTSERV.UTORONTO.CA (Linux 3.10.0) 12 5118 LS.KULEUVEN.BE (Linux 2.6.32) 13 5031 LISTSERV.TAMU.EDU (Linux 3.0.101) 14 4872 LISTS.UMN.EDU (Linux 3.10.0) 15 4191 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 4141 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 4096 LISTS.QUEENSU.CA (Linux 3.10.0) 18 4019 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 19 3659 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 3301 LIST.UVM.EDU (Linux 2.6.32)
Pos Recipients Site --- ---------- ---- 1 946280 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 2 817460 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 3 321658 LISTS.PSU.EDU (AIX 6.1) 4 229290 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 5 206957 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 188997 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 7 165398 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 157227 LISTS.UFL.EDU (Linux 2.6.32) 9 156818 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 10 154050 LISTSERV.UGA.EDU (Linux 2.6.32) 11 153513 LISTS.HAWAII.EDU (Linux 2.6.32-754.29.2.el6.x86_64) 12 149598 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 13 141699 LISTSERV.UA.EDU (Linux 4.12.14) 14 140875 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 140062 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 16 137860 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 17 131794 LISTES.ULAVAL.CA (Linux 3.10.0) 18 126055 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 121243 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 20 116504 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 59352 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 52531 ECF-EDNY@NYED.USCOURTS.GOV (Linux 3.10.0) 4 45168 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 41799 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 6 36455 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 8 33596 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 28309 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 13 27823 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 27709 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 15 27390 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 16 26419 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25522 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 18 25010 2019-STEM-EVENT-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition) 19 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 20 24350 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)