![[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 738944 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 358262 LISTS.PSU.EDU (Linux 3.10.0) 3 341209 LISTSERV.LIV.AC.UK (Linux 3.10.0) 4 291920 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 5 249079 LISTS.HAWAII.EDU (Linux 3.10.0-1160.45.1.el7.x86_64) 6 235091 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 7 186045 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 8 182868 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 9 176880 LISTES.ULAVAL.CA (Linux 3.10.0) 10 172194 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 161255 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 12 160132 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 13 160081 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 14 153632 LISTS.UFL.EDU (Linux 2.6.32) 15 131321 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 16 120821 LISTS.ROCHESTER.EDU (Windows Server 2012 R2 Standard x64 Edition) 17 119788 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 117578 LISTSERV.WUSTL.EDU (Windows Server 2016 Standard x64 Edition) 19 110728 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.45.1.el7.x86_64) 20 106462 MASSMAIL.VCU.EDU (Windows Server 2012 R2 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5560895 LISTES.ULAVAL.CA (Linux 3.10.0) 2 5081078 LISTS.PSU.EDU (Linux 3.10.0) 3 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 4 1691123 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 1492287 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1254578 LISTSERV.TAMU.EDU (Linux 3.0.101) 7 1086228 LISTSERV.UA.EDU (Linux 4.12.14) 8 1059533 LISTS.WAYNE.EDU (Linux 2.6.32) 9 1059036 LISTS.UFL.EDU (Linux 2.6.32) 10 1030832 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 11 938103 LIST.MSU.EDU (Linux 3.10.0) 12 934418 LISTS.UMN.EDU (Linux 3.10.0) 13 869185 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 14 863281 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 15 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 842796 LISTSERV.UH.EDU (Linux 3.10.0) 17 837282 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 18 828688 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 19 698197 LISTSERV.LIV.AC.UK (Linux 3.10.0) 20 685953 LISTS.QUEENSU.CA (Linux 3.10.0)
Pos Lists Site --- ----- ---- 1 34479 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16537 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 7130 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6764 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6143 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5162 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4987 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4799 LISTS.UMN.EDU (Linux 3.10.0) 13 4416 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4236 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3810 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 3752 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3424 LISTSERV.BROWN.EDU (Linux 3.10.0) 18 3393 LIST.UVM.EDU (Linux 2.6.32) 19 3286 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2772 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 708199 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 355324 LISTS.PSU.EDU (Linux 3.10.0) 3 333711 LISTSERV.LIV.AC.UK (Linux 3.10.0) 4 291273 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 5 247654 LISTS.HAWAII.EDU (Linux 3.10.0-1160.45.1.el7.x86_64) 6 180663 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 7 176709 LISTES.ULAVAL.CA (Linux 3.10.0) 8 168364 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 9 161010 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 10 159895 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 11 156988 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 12 152084 LISTS.UFL.EDU (Linux 2.6.32) 13 129384 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 14 122146 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 15 115063 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 110627 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.45.1.el7.x86_64) 17 103816 LISTSERV.UTORONTO.CA (Linux 3.10.0) 18 101787 LISTSERV.UA.EDU (Linux 4.12.14) 19 96632 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition) 20 94942 LISTS.WAYNE.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 41817 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 3 40427 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 4 39353 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33791 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 8 30227 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 28647 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 28277 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 12 27706 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 13 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 14 27381 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 15 27348 UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0) 16 26421 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 18 24633 ECF-MIWD@NYED.USCOURTS.GOV (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)