[LISTSERV - the mailing list management classic]

LISTSERV Top 20 statistics – September 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 (SEP21, 1-30)

Pos Recipients  Site
--- ----------  ----
  1     777829  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     706449  LISTSERV.TAMU.EDU (Linux 3.0.101)
  3     419588  LISTS.PSU.EDU (Linux 3.10.0)
  4     332157  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  5     281878  LISTES.ULAVAL.CA (Linux 3.10.0)
  6     242217  LIST.UNM.EDU (Linux 3.10.0-1160.36.2.el7.x86_64)
  7     240550  LISTS.HAWAII.EDU (Linux 3.10.0-1160.42.2.el7.x86_64)
  8     226940  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
  9     211704  LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition)
 10     192398  LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition)
 11     191900  LISTS.UFL.EDU (Linux 2.6.32)
 12     179374  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 13     176653  LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition)
 14     169883  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 15     169048  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 16     166426  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 17     162224  LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition)
 18     153147  LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64)
 19     142751  DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.31.1.el7.x86_64)
 20     142423  LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)

Top 20 sites by number of subscribers (30 Sep 2021)

Pos Subscribers  Site
--- -----------  ----
  1     5141934  LISTS.PSU.EDU (Linux 3.10.0)
  2     4601384  LISTES.ULAVAL.CA (Linux 3.10.0)
  3     1777535  LISTSERV.TAU.AC.IL (Linux 2.6.9)
  4     1649118  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
  5     1343093  LISTSERV.UTORONTO.CA (Linux 3.10.0)
  6     1245713  LISTSERV.TAMU.EDU (Linux 3.0.101)
  7     1059036  LISTS.UFL.EDU (Linux 2.6.32)
  8     1054900  LISTS.WAYNE.EDU (Linux 2.6.32)
  9     1038295  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 10     1015951  LISTSERV.UA.EDU (Linux 4.12.14)
 11      927690  LISTS.UMN.EDU (Linux 3.10.0)
 12      873793  LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition)
 13      871774  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 14      854389  LIST.MSU.EDU (Linux 3.10.0)
 15      853488  LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 16      845788  LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition)
 17      843644  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 18      829037  LISTSERV.UH.EDU (Linux 3.10.0)
 19      680285  LISTSERV.LIV.AC.UK (Linux 3.10.0)
 20      669734  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)

Top 20 sites by number of lists (30 Sep 2021)

Pos Lists  Site
--- -----  ----
  1 27860  LISTES.ULAVAL.CA (Linux 3.10.0)
  2 16471  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  7061  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  8  6759  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
  9  6050  LISTSERV.UTORONTO.CA (Linux 3.10.0)
 10  5104  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
 11  4992  LISTSERV.TAMU.EDU (Linux 3.0.101)
 12  4828  LISTS.UMN.EDU (Linux 3.10.0)
 13  4375  LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition)
 14  4210  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 15  3852  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 16  3755  LISTS.QUEENSU.CA (Linux 3.10.0)
 17  3440  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 18  3394  LISTSERV.BROWN.EDU (Linux 3.10.0)
 19  3372  LIST.UVM.EDU (Linux 2.6.32)
 20  2779  LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)

Top 20 sites by volume generated daily (SEP21, 1-30)

Pos Recipients  Site
--- ----------  ----
  1     746869  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     698015  LISTSERV.TAMU.EDU (Linux 3.0.101)
  3     416499  LISTS.PSU.EDU (Linux 3.10.0)
  4     324977  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  5     281723  LISTES.ULAVAL.CA (Linux 3.10.0)
  6     242061  LIST.UNM.EDU (Linux 3.10.0-1160.36.2.el7.x86_64)
  7     239880  LISTS.HAWAII.EDU (Linux 3.10.0-1160.42.2.el7.x86_64)
  8     223355  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
  9     190261  LISTS.UFL.EDU (Linux 2.6.32)
 10     176866  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 11     176266  LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition)
 12     166819  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 13     166182  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 14     164976  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 15     161995  LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition)
 16     159834  LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition)
 17     150908  LISTSERV.REDIRIS.ES (Linux 3.10.0-1062.9.1.el7.x86_64)
 18     142593  DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.31.1.el7.x86_64)
 19     140169  LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
 20     117140  LISTSERV.UTORONTO.CA (Linux 3.10.0)

Top 20 lists by number of subscribers (30 Sep 2021)

Pos Subscribers  Site
--- -----------  ----
  1       59191  CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
  2       54050  AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0)
  3       41929  SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
  4       41813  OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14)
  5       34587  TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition)
  6       33983  CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0)
  7       31621  TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
  8       28887  TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
  9       28667  HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
 10       28283  L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0)
 11       27707  RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 12       27479  TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9)
 13       27381  VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0)
 14       27348  UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0)
 15       26421  PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101)
 16       24992  NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0)
 17       24556  ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0)
 18       24288  EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 19       22770  STUDENT-TRAVEL-SURVEY-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition)
 20       21994  PRESIDENT-WELCOME@LISTSERV.TAU.AC.IL (Linux 2.6.9)