![[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 786695 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 594149 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 341561 LISTS.PSU.EDU (AIX 6.1) 4 326530 LISTSERV.LIV.AC.UK (Linux 2.6.32) 5 284002 LISTSERV.DOR.WA.GOV (Linux 3.10.0-1062.4.3.el7.x86_64) 6 263065 LISTES.ULAVAL.CA (Linux 3.10.0) 7 213870 LISTS.UFL.EDU (Linux 2.6.32) 8 212227 LISTSERV.UGA.EDU (Linux 2.6.32) 9 195725 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 10 189718 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 11 182231 LISTS.HAWAII.EDU (Linux 2.6.32-754.25.1.el6.x86_64) 12 177241 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 13 171783 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 14 155384 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 151796 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 16 147966 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 17 136111 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 18 129689 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 19 128841 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 20 121984 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5065895 LISTS.PSU.EDU (AIX 6.1) 2 3915475 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2248198 LS.KULEUVEN.BE (Linux 2.6.32) 4 1548082 LISTSERV.UGA.EDU (Linux 2.6.32) 5 1417407 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1282581 LISTSERV.UTORONTO.CA (Linux 3.10.0) 7 1281564 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1224033 LISTS.WAYNE.EDU (Linux 2.6.32) 9 1096274 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1059036 LISTS.UFL.EDU (Linux 2.6.32) 11 982099 LISTS.UMN.EDU (Linux 3.10.0) 12 944029 LIST.MSU.EDU (Linux 3.10.0) 13 864455 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 855538 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 850331 LISTSERV.UA.EDU (Linux 4.12.14) 16 835970 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 822736 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 818258 CUVMC.AIS.COLUMBIA.EDU (VM/SP 4.0) 19 784809 LISTSERV.UH.EDU (Linux 3.10.0) 20 748266 LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition)
Pos Lists Site --- ----- ---- 1 27620 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16558 LISTS.PSU.EDU (AIX 6.1) 3 12721 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 8153 MARIST (VM/SP 2.0) 7 8079 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 8 7233 LISTSERV.LIV.AC.UK (Linux 2.6.32) 9 6704 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 10 6514 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 6156 LISTSERV.UGA.EDU (Linux 2.6.32) 12 5467 LISTS.UMN.EDU (Linux 3.10.0) 13 5049 LISTSERV.TAMU.EDU (Linux 3.0.101) 14 4939 LS.KULEUVEN.BE (Linux 2.6.32) 15 4372 LISTSERV.UTORONTO.CA (Linux 3.10.0) 16 4171 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 17 4073 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 3998 LISTS.QUEENSU.CA (Linux 3.10.0) 19 3907 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 20 3567 LISTSERV.BUFFALO.EDU (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 757878 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 593161 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 337626 LISTS.PSU.EDU (AIX 6.1) 4 315935 LISTSERV.LIV.AC.UK (Linux 2.6.32) 5 283317 LISTSERV.DOR.WA.GOV (Linux 3.10.0-1062.4.3.el7.x86_64) 6 262912 LISTES.ULAVAL.CA (Linux 3.10.0) 7 212612 LISTS.UFL.EDU (Linux 2.6.32) 8 207694 LISTSERV.UGA.EDU (Linux 2.6.32) 9 180538 LISTS.HAWAII.EDU (Linux 2.6.32-754.25.1.el6.x86_64) 10 174558 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 11 168983 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 12 151108 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 13 150640 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 14 148980 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 15 145588 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 16 129472 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 17 128820 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 18 128053 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 19 121571 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 20 117989 LISTSERV.UTORONTO.CA (Linux 3.10.0)
Pos Subscribers Site --- ----------- ---- 1 300656 COMPUTING@LIST.MSU.EDU (Linux 3.10.0) 2 59384 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 3 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 4 43980 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 41763 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 6 36688 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 8 33600 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 9 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 10 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 11 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 12 28310 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 13 28081 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 27709 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 15 27399 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 16 26419 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 17 25008 2019-STEM-EVENT-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition) 18 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 19 24688 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 20 24440 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)