![[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 561044 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 526276 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 272669 LISTS.PSU.EDU (Linux 3.10.0) 4 219891 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 5 196014 LISTSERV.LIV.AC.UK (Linux 3.10.0) 6 178633 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 7 156393 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 8 151106 LISTS.HAWAII.EDU (Linux 3.10.0-1160.71.1.el7.x86_64) 9 133162 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 10 132338 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 11 115345 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 12 111253 LISTS.UFL.EDU (Linux 2.6.32) 13 109751 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 107788 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 15 103697 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 98830 LISTS.ROCHESTER.EDU (Windows Server 2012 R2 Standard x64 Edition) 17 96226 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 18 95264 LISTES.ULAVAL.CA (Linux 3.10.0) 19 86695 MASSMAIL.VCU.EDU (Windows Server 2016 Datacenter x64 Edition) 20 85605 LISTS.PORTSIDE.ORG (Linux 4.9.0-17-amd64)
Pos Subscribers Site --- ----------- ---- 1 5648581 LISTES.ULAVAL.CA (Linux 3.10.0) 2 5151528 LISTS.PSU.EDU (Linux 3.10.0) 3 1866364 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1402273 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1226640 LISTSERV.UA.EDU (Linux 4.12.14) 7 1198822 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1059036 LISTS.UFL.EDU (Linux 2.6.32) 9 1047202 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 1017877 LISTS.WAYNE.EDU (Linux 2.6.32) 11 943712 LISTS.UMN.EDU (Linux 3.10.0) 12 911210 LIST.MSU.EDU (Linux 3.10.0) 13 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 845133 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 15 832896 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 829046 LISTSERV.UH.EDU (Linux 3.10.0) 17 823130 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 18 796052 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 19 703623 LISTS.QUEENSU.CA (Linux 3.10.0) 20 687696 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
Pos Lists Site --- ----- ---- 1 34878 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16663 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 7175 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6774 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6368 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5369 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 4977 LISTSERV.TAMU.EDU (Linux 3.0.101) 12 4822 LISTS.UMN.EDU (Linux 3.10.0) 13 4489 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4319 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3882 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 3869 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3549 LIST.UVM.EDU (Linux 2.6.32) 18 3489 LISTSERV.BROWN.EDU (Linux 3.10.0) 19 3312 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2797 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 534404 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 525740 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 3 269590 LISTS.PSU.EDU (Linux 3.10.0) 4 219675 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 5 189827 LISTSERV.LIV.AC.UK (Linux 3.10.0) 6 153413 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 7 149001 LISTS.HAWAII.EDU (Linux 3.10.0-1160.71.1.el7.x86_64) 8 132984 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 9 130476 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 113833 LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64) 11 109716 LISTS.UFL.EDU (Linux 2.6.32) 12 107505 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 13 101468 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 14 95093 LISTES.ULAVAL.CA (Linux 3.10.0) 15 92142 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 85582 LISTS.PORTSIDE.ORG (Linux 4.9.0-17-amd64) 17 85483 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 18 85235 LIST.UNM.EDU (Linux 3.10.0-1160.71.1.el7.x86_64) 19 82238 LISTSERV.ICORS.ORG (Windows Server 2016 Datacenter x64 Edition) 20 82057 LIST.UVM.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 2 42139 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 3 41824 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 4 39313 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 5 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 6 33098 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 8 30195 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 28392 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)