[LISTSERV - the mailing list management classic]

LISTSERV Top 20 statistics – 15 April 2021


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).

What do these numbers mean exactly?

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).


Top 20 sites by volume delivered daily (APR21, 1-15)

Pos Recipients  Site
--- ----------  ----
  1     694875  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     617039  LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition)
  3     526130  LISTSERV.TAMU.EDU (Linux 3.0.101)
  4     431968  LISTS.PSU.EDU (Linux 3.10.0)
  5     418479  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  6     307377  LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
  7     284462  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
  8     244828  LISTES.ULAVAL.CA (Linux 3.10.0)
  9     241868  LISTS.UFL.EDU (Linux 2.6.32)
 10     233952  LISTSERV.UGA.EDU (Linux 2.6.32)
 11     224774  LISTS.HAWAII.EDU (Linux 2.6.32-754.36.1.el6.x86_64)
 12     203033  LISTSERV.TDBANK.CA (Windows Server 2012 R2 Datacenter x64 Edition)
 13     200416  LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition)
 14     198385  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 15     190801  LISTS.APA.ORG (Windows Server 2016 Datacenter x64 Edition)
 16     172814  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 17     169656  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 18     165416  LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition)
 19     160588  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 20     158185  LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)

Top 20 sites by number of subscribers (15 Apr 2021)

Pos Subscribers  Site
--- -----------  ----
  1     5090048  LISTES.ULAVAL.CA (Linux 3.10.0)
  2     4976585  LISTS.PSU.EDU (Linux 3.10.0)
  3     2299124  LS.KULEUVEN.BE (Linux 2.6.32)
  4     1750920  LISTSERV.TAU.AC.IL (Linux 2.6.9)
  5     1506524  LISTSERV.UGA.EDU (Linux 2.6.32)
  6     1298127  LISTS.WAYNE.EDU (Linux 2.6.32)
  7     1269558  LISTSERV.UTORONTO.CA (Linux 3.10.0)
  8     1220410  LISTSERV.TAMU.EDU (Linux 3.0.101)
  9     1157570  LISTSERV.UA.EDU (Linux 4.12.14)
 10     1135640  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 11     1124929  LIST.MSU.EDU (Linux 3.10.0)
 12     1059036  LISTS.UFL.EDU (Linux 2.6.32)
 13      946792  LISTS.UMN.EDU (Linux 3.10.0)
 14      884237  LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition)
 15      865429  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 16      837000  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 17      833894  LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 18      833294  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 19      786419  LISTSERV.UH.EDU (Linux 3.10.0)
 20      689998  LISTSERV.LIV.AC.UK (Linux 3.10.0)

Top 20 sites by number of lists (15 Apr 2021)

Pos Lists  Site
--- -----  ----
  1 30536  LISTES.ULAVAL.CA (Linux 3.10.0)
  2 17022  LISTS.PSU.EDU (Linux 3.10.0)
  3 14066  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  7566  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  8  6739  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
  9  5812  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 10  5775  LISTSERV.UTORONTO.CA (Linux 3.10.0)
 11  5347  LS.KULEUVEN.BE (Linux 2.6.32)
 12  5015  LISTSERV.TAMU.EDU (Linux 3.0.101)
 13  4939  LISTSERV.UGA.EDU (Linux 2.6.32)
 14  4872  LISTS.UMN.EDU (Linux 3.10.0)
 15  4273  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 16  4208  LISTS.QUEENSU.CA (Linux 3.10.0)
 17  3781  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 18  3656  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 19  3365  LIST.UVM.EDU (Linux 2.6.32)
 20  3343  LISTSERV.BROWN.EDU (Linux 3.10.0)

Top 20 sites by volume generated daily (APR21, 1-15)

Pos Recipients  Site
--- ----------  ----
  1     665694  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     616344  LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition)
  3     520825  LISTSERV.TAMU.EDU (Linux 3.0.101)
  4     428786  LISTS.PSU.EDU (Linux 3.10.0)
  5     409798  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  6     307025  LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
  7     244479  LISTES.ULAVAL.CA (Linux 3.10.0)
  8     240250  LISTS.UFL.EDU (Linux 2.6.32)
  9     229646  LISTSERV.UGA.EDU (Linux 2.6.32)
 10     223193  LISTS.HAWAII.EDU (Linux 2.6.32-754.36.1.el6.x86_64)
 11     195791  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 12     187762  LISTS.APA.ORG (Windows Server 2016 Datacenter x64 Edition)
 13     179309  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 14     170827  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 15     169385  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 16     165232  LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition)
 17     155695  LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
 18     155489  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 19     146887  LISTSERV.UTORONTO.CA (Linux 3.10.0)
 20     139477  LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64)

Top 20 lists by number of subscribers (15 Apr 2021)

Pos Subscribers  Site
--- -----------  ----
  1       59235  CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32)
  2       54050  AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0)
  3       43408  SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
  4       41810  OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14)
  5       34587  TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition)
  6       34000  CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0)
  7       33576  L-SMEAL-REPORT@LISTS.PSU.EDU (Linux 3.10.0)
  8       32997  TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
  9       30835  FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32)
 10       29647  TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
 11       28918  BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32)
 12       28918  BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32)
 13       28302  L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0)
 14       27707  RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 15       27480  TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9)
 16       27390  VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0)
 17       26924  HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32)
 18       26419  PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101)
 19       25580  ISMA@LS.KULEUVEN.BE (Linux 2.6.32)
 20       24992  NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0)