[LISTSERV - the mailing list management classic]

LISTSERV Top 20 statistics – March 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 (MAR21, 1-28)

Pos Recipients  Site
--- ----------  ----
  1     926890  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     562836  LISTSERV.TAMU.EDU (Linux 3.0.101)
  3     448936  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  4     445335  LISTS.PSU.EDU (Linux 3.10.0)
  5     373489  LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition)
  6     294086  LISTES.ULAVAL.CA (Linux 3.10.0)
  7     289374  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
  8     253373  LISTSERV.UGA.EDU (Linux 2.6.32)
  9     241853  DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.11.1.el7.x86_64)
 10     233014  LISTS.HAWAII.EDU (Linux 2.6.32-754.36.1.el6.x86_64)
 11     226742  LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition)
 12     223946  LISTS.UFL.EDU (Linux 2.6.32)
 13     196316  LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition)
 14     195256  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 15     194068  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 16     193324  LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64)
 17     186060  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 18     172541  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 19     151995  LIST.UNM.EDU (Linux 3.10.0-1160.6.1.el7.x86_64)
 20     143871  LISTSERV.UTORONTO.CA (Linux 3.10.0)

Top 20 sites by number of subscribers (28 Mar 2021)

Pos Subscribers  Site
--- -----------  ----
  1     4877473  LISTS.PSU.EDU (Linux 3.10.0)
  2     4470874  LISTES.ULAVAL.CA (Linux 3.10.0)
  3     2292766  LS.KULEUVEN.BE (Linux 2.6.32)
  4     1750127  LISTSERV.TAU.AC.IL (Linux 2.6.9)
  5     1333466  LISTSERV.UTORONTO.CA (Linux 3.10.0)
  6     1268260  LISTS.WAYNE.EDU (Linux 2.6.32)
  7     1255398  LISTSERV.TAMU.EDU (Linux 3.0.101)
  8     1128815  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
  9     1120733  LIST.MSU.EDU (Linux 3.10.0)
 10     1059036  LISTS.UFL.EDU (Linux 2.6.32)
 11      972040  LISTSERV.UA.EDU (Linux 4.12.14)
 12      946016  LISTS.UMN.EDU (Linux 3.10.0)
 13      889815  LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition)
 14      867458  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 15      855419  LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 16      836487  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 17      835576  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 18      784514  LISTSERV.UH.EDU (Linux 3.10.0)
 19      700637  LISTSERV.LIV.AC.UK (Linux 3.10.0)
 20      688048  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)

Top 20 sites by number of lists (28 Mar 2021)

Pos Lists  Site
--- -----  ----
  1 27510  LISTES.ULAVAL.CA (Linux 3.10.0)
  2 17010  LISTS.PSU.EDU (Linux 3.10.0)
  3 13899  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  7565  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  8  6737  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
  9  5802  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 10  5761  LISTSERV.UTORONTO.CA (Linux 3.10.0)
 11  5338  LS.KULEUVEN.BE (Linux 2.6.32)
 12  5015  LISTSERV.TAMU.EDU (Linux 3.0.101)
 13  4869  LISTS.UMN.EDU (Linux 3.10.0)
 14  4265  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 15  4211  LISTS.QUEENSU.CA (Linux 3.10.0)
 16  3776  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 17  3719  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 18  3367  LIST.UVM.EDU (Linux 2.6.32)
 19  3338  LISTSERV.BROWN.EDU (Linux 3.10.0)
 20  2727  LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)

Top 20 sites by volume generated daily (MAR21, 1-28)

Pos Recipients  Site
--- ----------  ----
  1     894763  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     559422  LISTSERV.TAMU.EDU (Linux 3.0.101)
  3     441778  LISTS.PSU.EDU (Linux 3.10.0)
  4     435651  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  5     372887  LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition)
  6     293752  LISTES.ULAVAL.CA (Linux 3.10.0)
  7     248618  LISTSERV.UGA.EDU (Linux 2.6.32)
  8     241602  DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.11.1.el7.x86_64)
  9     231674  LISTS.HAWAII.EDU (Linux 2.6.32-754.36.1.el6.x86_64)
 10     222035  LISTS.UFL.EDU (Linux 2.6.32)
 11     203372  LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 12     196084  LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition)
 13     191914  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 14     190916  LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64)
 15     185538  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 16     181520  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 17     172300  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 18     151771  LIST.UNM.EDU (Linux 3.10.0-1160.6.1.el7.x86_64)
 19     143761  LISTSERV.UTORONTO.CA (Linux 3.10.0)
 20     134481  LISTSERV.UA.EDU (Linux 4.12.14)

Top 20 lists by number of subscribers (28 Mar 2021)

Pos Subscribers  Site
--- -----------  ----
  1       54050  AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0)
  2       43374  SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
  3       41809  OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14)
  4       34587  TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition)
  5       34000  CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0)
  6       33577  L-SMEAL-REPORT@LISTS.PSU.EDU (Linux 3.10.0)
  7       33213  TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
  8       30835  FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32)
  9       29732  TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
 10       28918  BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32)
 11       28918  BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32)
 12       28302  L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0)
 13       27707  RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 14       27480  TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9)
 15       27390  VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0)
 16       26418  PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101)
 17       25579  ISMA@LS.KULEUVEN.BE (Linux 2.6.32)
 18       24992  NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0)
 19       24304  EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 20       23331  ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0)