![[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 788253 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 304811 LISTS.PSU.EDU (AIX 6.1) 3 221639 LISTSERV.TAMU.EDU (Linux 3.0.101) 4 199233 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 5 199123 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 194169 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 7 169806 LISTSERV.UGA.EDU (Linux 2.6.32) 8 165849 LISTS.UFL.EDU (Linux 2.6.32) 9 163881 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 10 157631 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 11 157568 LISTS.HAWAII.EDU (Linux 2.6.32-754.29.2.el6.x86_64) 12 147441 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 13 143788 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 14 139799 LISTSERV.UA.EDU (Linux 4.12.14) 15 139507 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 16 138446 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1127.8.2.el7.x86_64) 17 135752 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 132788 LIST.UNM.EDU (Linux 2.6.32-754.30.2.el6.x86_64) 19 131450 LISTSERV.TDBANK.CA (Windows Server 2012 R2 Datacenter x64 Edition) 20 125512 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 4847976 LISTS.PSU.EDU (AIX 6.1) 2 4146310 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2269896 LS.KULEUVEN.BE (Linux 2.6.32) 4 1643445 LISTSERV.UGA.EDU (Linux 2.6.32) 5 1462104 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1323573 LISTS.WAYNE.EDU (Linux 2.6.32) 7 1207163 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1200670 LISTSERV.UTORONTO.CA (Linux 3.10.0) 9 1090008 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1059036 LISTS.UFL.EDU (Linux 2.6.32) 11 987259 LIST.MSU.EDU (Linux 3.10.0) 12 973420 LISTS.UMN.EDU (Linux 3.10.0) 13 833451 LISTSERV.UA.EDU (Linux 4.12.14) 14 829172 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 821932 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 818799 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 786539 LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 18 774160 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 19 749325 LISTSERV.UH.EDU (Linux 3.10.0) 20 726106 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Lists Site --- ----- ---- 1 27651 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16569 LISTS.PSU.EDU (AIX 6.1) 3 14180 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 7475 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 6723 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6279 LISTSERV.UGA.EDU (Linux 2.6.32) 10 5663 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 5413 LISTSERV.UTORONTO.CA (Linux 3.10.0) 12 5124 LS.KULEUVEN.BE (Linux 2.6.32) 13 5028 LISTSERV.TAMU.EDU (Linux 3.0.101) 14 4871 LISTS.UMN.EDU (Linux 3.10.0) 15 4187 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 4153 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 4119 LISTS.QUEENSU.CA (Linux 3.10.0) 18 4022 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 19 3656 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 3304 LIST.UVM.EDU (Linux 2.6.32)
Pos Recipients Site --- ---------- ---- 1 758937 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 302160 LISTS.PSU.EDU (AIX 6.1) 3 220808 LISTSERV.TAMU.EDU (Linux 3.0.101) 4 193613 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 5 192138 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 166470 LISTSERV.UGA.EDU (Linux 2.6.32) 7 163895 LISTS.UFL.EDU (Linux 2.6.32) 8 157281 LISTS.HAWAII.EDU (Linux 2.6.32-754.29.2.el6.x86_64) 9 155334 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 10 147121 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 11 141822 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 12 139328 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 13 138337 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1127.8.2.el7.x86_64) 14 136566 LISTSERV.UA.EDU (Linux 4.12.14) 15 132565 LIST.UNM.EDU (Linux 2.6.32-754.30.2.el6.x86_64) 16 131356 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 17 123371 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 18 121440 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 19 112722 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 102149 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 59349 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 48210 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 41799 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 6 36449 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 27736 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 24345 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)