[LISTSERV - the mailing list management classic]

LISTSERV Top 20 statistics – July 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 (JUL21, 1-29)

Pos Recipients  Site
--- ----------  ----
  1     656630  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     244206  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  3     243228  LISTS.PSU.EDU (Linux 3.10.0)
  4     187234  LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition)
  5     172974  LISTSERV.TAMU.EDU (Linux 3.0.101)
  6     152609  DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.25.1.el7.x86_64)
  7     126884  LISTS.UFL.EDU (Linux 2.6.32)
  8     123654  LISTS.HAWAII.EDU (Linux 3.10.0-1160.31.1.el7.x86_64)
  9     121722  LISTSERV.TDBANK.CA (Windows Server 2012 R2 Datacenter x64 Edition)
 10     117225  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
 11     113821  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 12     106435  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 13     104228  MASSMAIL.VCU.EDU (Windows Server 2012 R2 Datacenter x64 Edition)
 14     100458  LISTES.ULAVAL.CA (Linux 3.10.0)
 15      98535  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 16      95770  LISTS.ROCHESTER.EDU (Windows Server 2012 R2 Standard x64 Edition)
 17      95465  LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition)
 18      95418  LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
 19      94717  LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition)
 20      93580  LISTSERV.BUFFALO.EDU (Linux 3.10.0)

Top 20 sites by number of subscribers (29 Jul 2021)

Pos Subscribers  Site
--- -----------  ----
  1     5471642  LISTES.ULAVAL.CA (Linux 3.10.0)
  2     4952183  LISTS.PSU.EDU (Linux 3.10.0)
  3     1777535  LISTSERV.TAU.AC.IL (Linux 2.6.9)
  4     1569586  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
  5     1268028  LISTS.WAYNE.EDU (Linux 2.6.32)
  6     1254071  LISTSERV.TAMU.EDU (Linux 3.0.101)
  7     1171263  LISTSERV.UTORONTO.CA (Linux 3.10.0)
  8     1059036  LISTS.UFL.EDU (Linux 2.6.32)
  9     1034355  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 10      976271  LISTSERV.UA.EDU (Linux 4.12.14)
 11      934912  LISTS.UMN.EDU (Linux 3.10.0)
 12      853488  LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
 13      833206  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 14      806338  LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition)
 15      801667  LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition)
 16      790237  LISTSERV.UH.EDU (Linux 3.10.0)
 17      752201  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 18      709597  LIST.MSU.EDU (Linux 3.10.0)
 19      686565  LISTSERV.LIV.AC.UK (Linux 3.10.0)
 20      676184  LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)

Top 20 sites by number of lists (29 Jul 2021)

Pos Lists  Site
--- -----  ----
  1 34077  LISTES.ULAVAL.CA (Linux 3.10.0)
  2 17187  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  7622  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  8  6748  LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
  9  5959  LISTSERV.UTORONTO.CA (Linux 3.10.0)
 10  4999  LISTSERV.TAMU.EDU (Linux 3.0.101)
 11  4985  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
 12  4879  LISTS.UMN.EDU (Linux 3.10.0)
 13  4325  LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition)
 14  4161  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 15  3803  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 16  3716  LISTS.QUEENSU.CA (Linux 3.10.0)
 17  3591  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 18  3380  LIST.UVM.EDU (Linux 2.6.32)
 19  3355  LISTSERV.BROWN.EDU (Linux 3.10.0)
 20  2746  LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)

Top 20 sites by volume generated daily (JUL21, 1-29)

Pos Recipients  Site
--- ----------  ----
  1     628525  JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition)
  2     240181  LISTS.PSU.EDU (Linux 3.10.0)
  3     237624  LISTSERV.LIV.AC.UK (Linux 3.10.0)
  4     168597  LISTSERV.TAMU.EDU (Linux 3.0.101)
  5     152456  DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.25.1.el7.x86_64)
  6     125266  LISTS.UFL.EDU (Linux 2.6.32)
  7     123259  LISTS.HAWAII.EDU (Linux 3.10.0-1160.31.1.el7.x86_64)
  8     115495  LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
  9     113638  LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64)
 10     104764  LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition)
 11     100234  LISTES.ULAVAL.CA (Linux 3.10.0)
 12      95679  LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
 13      94350  LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition)
 14      93166  LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition)
 15      93107  LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
 16      89329  LISTSERV.BUFFALO.EDU (Linux 3.10.0)
 17      88891  LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition)
 18      81040  LISTSERV.UA.EDU (Linux 4.12.14)
 19      80922  L.GOP.COM (Windows Server 2016 Standard x64 Edition)
 20      76571  LIST.MSU.EDU (Linux 3.10.0)

Top 20 lists by number of subscribers (29 Jul 2021)

Pos Subscribers  Site
--- -----------  ----
  1       59211  CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
  2       54050  AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0)
  3       47375  SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition)
  4       41812  OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14)
  5       34587  TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition)
  6       33992  CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0)
  7       33543  L-SMEAL-REPORT@LISTS.PSU.EDU (Linux 3.10.0)
  8       31621  TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
  9       30835  FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32)
 10       28887  TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9)
 11       28365  HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition)
 12       28288  L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0)
 13       27707  RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition)
 14       27479  TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9)
 15       27382  VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0)
 16       27348  UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0)
 17       26421  PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101)
 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       23331  ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0)