![[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 703635 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 367547 LISTS.PSU.EDU (Linux 3.10.0) 3 291977 LISTES.ULAVAL.CA (Linux 3.10.0) 4 277566 LISTSERV.LIV.AC.UK (Linux 3.10.0) 5 238101 LISTS.HAWAII.EDU (Linux 3.10.0-1160.71.1.el7.x86_64) 6 228235 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 7 207905 LISTS.UFL.EDU (Linux 2.6.32) 8 206418 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 204623 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 10 202103 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 11 186485 LIST.UNM.EDU (Linux 3.10.0-1160.71.1.el7.x86_64) 12 185301 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 13 178810 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 14 175014 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 15 170539 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 16 166507 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 17 162865 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 18 153499 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 19 109937 MASSMAIL.VCU.EDU (Windows Server 2016 Datacenter x64 Edition) 20 107726 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5173957 LISTS.PSU.EDU (Linux 3.10.0) 2 4718646 LISTES.ULAVAL.CA (Linux 3.10.0) 3 1849944 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1512349 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1238031 LISTSERV.UA.EDU (Linux 4.12.14) 7 1188010 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1073718 LISTS.WAYNE.EDU (Linux 2.6.32) 9 1059036 LISTS.UFL.EDU (Linux 2.6.32) 10 1053670 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 11 1033906 LIST.MSU.EDU (Linux 3.10.0) 12 930388 LISTS.UMN.EDU (Linux 3.10.0) 13 886152 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 848230 LISTSERV.UH.EDU (Linux 3.10.0) 16 846245 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 783660 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 18 737949 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 19 704437 LISTS.QUEENSU.CA (Linux 3.10.0) 20 690085 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
Pos Lists Site --- ----- ---- 1 28234 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16720 LISTS.PSU.EDU (Linux 3.10.0) 3 14174 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 7192 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6777 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6418 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5401 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4977 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4833 LISTS.UMN.EDU (Linux 3.10.0) 13 4499 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4331 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3884 LISTS.QUEENSU.CA (Linux 3.10.0) 16 3866 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 17 3525 LIST.UVM.EDU (Linux 2.6.32) 18 3516 LISTSERV.BROWN.EDU (Linux 3.10.0) 19 3314 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2803 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 672982 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 364824 LISTS.PSU.EDU (Linux 3.10.0) 3 291806 LISTES.ULAVAL.CA (Linux 3.10.0) 4 270200 LISTSERV.LIV.AC.UK (Linux 3.10.0) 5 236463 LISTS.HAWAII.EDU (Linux 3.10.0-1160.71.1.el7.x86_64) 6 227966 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 7 205976 LISTS.UFL.EDU (Linux 2.6.32) 8 202786 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 186367 LIST.UNM.EDU (Linux 3.10.0-1160.71.1.el7.x86_64) 10 183157 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 11 178615 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 12 171597 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 13 170173 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 14 162624 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 15 162237 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 151639 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 17 134414 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 18 105584 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 19 101927 LISTSERV.UTORONTO.CA (Linux 3.10.0) 20 100080 LISTSERV.BROWN.EDU (Linux 3.10.0)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 42714 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 3 41825 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 4 39305 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33096 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 8 30186 UG2021FALL@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 28887 TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 10 28653 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 28263 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 12 27705 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 13 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 14 27375 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 15 27347 UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0) 16 26421 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25025 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0) 18 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 19 24288 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 22770 STUDENT-TRAVEL-SURVEY-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition)