![[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 1210264 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 2 789294 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 3 411397 LISTS.PSU.EDU (AIX 6.1) 4 265997 LISTSERV.TAMU.EDU (Linux 3.0.101) 5 241282 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 6 239958 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 7 229814 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 8 208795 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 9 207675 LISTS.HAWAII.EDU (Linux 2.6.32-754.28.1.el6.x86_64) 10 203978 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 11 200673 LISTSERV.UGA.EDU (Linux 2.6.32) 12 191553 LISTSERV.LIV.AC.UK (Linux 2.6.32) 13 178564 LISTSERV.UA.EDU (Linux 4.12.14) 14 176248 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 15 173638 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 166721 LISTS.UFL.EDU (Linux 2.6.32) 17 166476 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 18 163293 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 19 151513 LISTES.ULAVAL.CA (Linux 3.10.0) 20 150233 LIST.UVM.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 4847976 LISTS.PSU.EDU (AIX 6.1) 2 4568934 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2282892 LS.KULEUVEN.BE (Linux 2.6.32) 4 1578630 LISTSERV.UGA.EDU (Linux 2.6.32) 5 1455488 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1311310 LISTSERV.UTORONTO.CA (Linux 3.10.0) 7 1225904 LISTS.WAYNE.EDU (Linux 2.6.32) 8 1214713 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 1129026 LIST.MSU.EDU (Linux 3.10.0) 10 1090567 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 1059036 LISTS.UFL.EDU (Linux 2.6.32) 12 970443 LISTS.UMN.EDU (Linux 3.10.0) 13 865456 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 852031 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 846307 LISTSERV.UA.EDU (Linux 4.12.14) 16 844982 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 836470 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 793614 LISTSERV.UH.EDU (Linux 3.10.0) 19 775361 LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 20 690746 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Lists Site --- ----- ---- 1 30843 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16569 LISTS.PSU.EDU (AIX 6.1) 3 13737 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 7361 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 6719 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6236 LISTSERV.UGA.EDU (Linux 2.6.32) 10 5638 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 5259 LISTSERV.UTORONTO.CA (Linux 3.10.0) 12 5052 LS.KULEUVEN.BE (Linux 2.6.32) 13 5034 LISTSERV.TAMU.EDU (Linux 3.0.101) 14 4867 LISTS.UMN.EDU (Linux 3.10.0) 15 4186 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 4116 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 4031 LISTS.QUEENSU.CA (Linux 3.10.0) 18 4009 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 19 3625 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 3286 LIST.UVM.EDU (Linux 2.6.32)
Pos Recipients Site --- ---------- ---- 1 1207886 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 2 760503 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 3 406915 LISTS.PSU.EDU (AIX 6.1) 4 265225 LISTSERV.TAMU.EDU (Linux 3.0.101) 5 239481 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 6 208597 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 7 207148 LISTS.HAWAII.EDU (Linux 2.6.32-754.28.1.el6.x86_64) 8 201300 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 9 196479 LISTSERV.UGA.EDU (Linux 2.6.32) 10 184628 LISTSERV.LIV.AC.UK (Linux 2.6.32) 11 179176 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 12 173690 LISTSERV.UA.EDU (Linux 4.12.14) 13 173572 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 14 168591 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 166179 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 16 165406 LISTS.UFL.EDU (Linux 2.6.32) 17 163118 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 18 151296 LISTES.ULAVAL.CA (Linux 3.10.0) 19 148545 LIST.UVM.EDU (Linux 2.6.32) 20 146409 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 59366 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 52359 ECF-EDNY@NYED.USCOURTS.GOV (Linux 3.10.0) 4 44431 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 41797 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 6 36457 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 28004 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 27709 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 15 27398 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 16 26419 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25009 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 24693 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 20 24405 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)