![[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 623636 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 329544 LISTS.PSU.EDU (AIX 6.1) 3 267860 LISTSERV.LIV.AC.UK (Linux 2.6.32) 4 199685 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 5 193397 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 6 186100 LISTSERV.TAMU.EDU (Linux 3.0.101) 7 177630 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 8 167632 LISTS.UFL.EDU (Linux 2.6.32) 9 166346 LISTS.HAWAII.EDU (Linux 2.6.32-754.35.1.el6.x86_64) 10 158334 LISTES.ULAVAL.CA (Linux 3.10.0) 11 149289 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 12 142518 LISTSERV.UGA.EDU (Linux 2.6.32) 13 141962 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 129980 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 15 123275 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 117736 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 17 110569 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 18 107692 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 19 102569 LISTSERV.WUSTL.EDU (Windows Server 2016 Standard x64 Edition) 20 100106 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5188324 LISTES.ULAVAL.CA (Linux 3.10.0) 2 4923378 LISTS.PSU.EDU (AIX 6.1) 3 2245367 LS.KULEUVEN.BE (Linux 2.6.32) 4 1579325 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1453789 LISTSERV.UGA.EDU (Linux 2.6.32) 6 1284519 LISTS.WAYNE.EDU (Linux 2.6.32) 7 1217494 LISTSERV.UTORONTO.CA (Linux 3.10.0) 8 1176607 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 1132317 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1093334 LIST.MSU.EDU (Linux 3.10.0) 11 1059036 LISTS.UFL.EDU (Linux 2.6.32) 12 962700 LISTS.UMN.EDU (Linux 3.10.0) 13 941393 LISTSERV.UA.EDU (Linux 4.12.14) 14 922941 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 850947 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 826900 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 822583 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 811467 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 19 804692 LISTSERV.UH.EDU (Linux 3.10.0) 20 743438 LISTS.MAINE.EDU (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 34750 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16993 LISTS.PSU.EDU (AIX 6.1) 3 11838 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 7513 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 6734 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 5779 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 5482 LISTSERV.UTORONTO.CA (Linux 3.10.0) 11 5258 LS.KULEUVEN.BE (Linux 2.6.32) 12 5024 LISTSERV.TAMU.EDU (Linux 3.0.101) 13 4912 LISTS.UMN.EDU (Linux 3.10.0) 14 4854 LISTSERV.UGA.EDU (Linux 2.6.32) 15 4225 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 4161 LISTS.QUEENSU.CA (Linux 3.10.0) 17 4001 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 18 3837 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 19 3710 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 3337 LISTSERV.BROWN.EDU (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 597636 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 326456 LISTS.PSU.EDU (AIX 6.1) 3 259267 LISTSERV.LIV.AC.UK (Linux 2.6.32) 4 191149 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 5 185313 LISTSERV.TAMU.EDU (Linux 3.0.101) 6 177042 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 7 166299 LISTS.UFL.EDU (Linux 2.6.32) 8 165658 LISTS.HAWAII.EDU (Linux 2.6.32-754.35.1.el6.x86_64) 9 158091 LISTES.ULAVAL.CA (Linux 3.10.0) 10 149105 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 11 139528 LISTSERV.UGA.EDU (Linux 2.6.32) 12 129792 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 13 117954 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 14 115827 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 15 110223 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 16 103655 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 17 98469 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 18 92916 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 90795 LISTS.WAYNE.EDU (Linux 2.6.32) 20 88332 LIST.UVM.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 59282 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 42232 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 4 41805 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 5 36016 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 6 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 7 33582 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 8 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 9 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 10 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 11 28305 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 12 27708 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 13 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 14 27390 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 15 27288 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 16 26418 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25575 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 18 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 19 24317 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 23332 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0)