![[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 765644 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 503066 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 476579 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 4 388680 LISTS.PSU.EDU (AIX 6.1) 5 303990 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 283495 LISTES.ULAVAL.CA (Linux 3.10.0) 7 236107 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 8 221308 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 9 213499 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 10 210832 LISTSERV.UGA.EDU (Linux 2.6.32) 11 190194 LISTS.HAWAII.EDU (Linux 2.6.32-754.23.1.el6.x86_64) 12 189912 LISTS.UFL.EDU (Linux 2.6.32) 13 183917 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 14 182125 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 15 180342 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 16 154829 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 17 152200 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 18 138357 LISTSERV.UA.EDU (Linux 4.12.14) 19 132611 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 126509 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 5046248 LISTS.PSU.EDU (AIX 6.1) 2 3969271 LISTES.ULAVAL.CA (Linux 3.10.0) 3 2212521 LS.KULEUVEN.BE (Linux 2.6.32) 4 1490031 LISTSERV.UGA.EDU (Linux 2.6.32) 5 1391971 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1303778 LISTSERV.TAMU.EDU (Linux 3.0.101) 7 1282581 LISTSERV.UTORONTO.CA (Linux 3.10.0) 8 1241063 LISTS.WAYNE.EDU (Linux 2.6.32) 9 1126100 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1059036 LISTS.UFL.EDU (Linux 2.6.32) 11 1022084 LISTSERV.UH.EDU (Linux 3.10.0) 12 982099 LISTS.UMN.EDU (Linux 2.6.32) 13 944029 LIST.MSU.EDU (Linux 3.10.0) 14 857586 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 15 850091 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 16 843607 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 828744 LISTSERV.UA.EDU (Linux 4.12.14) 18 819163 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 818258 CUVMC.AIS.COLUMBIA.EDU (VM/SP 4.0) 20 737040 LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition)
Pos Lists Site --- ----- ---- 1 27625 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16510 LISTS.PSU.EDU (AIX 6.1) 3 13967 LISTSERV.UH.EDU (Linux 3.10.0) 4 12060 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 9788 LISTS.CLEMSON.EDU (Linux 2.6.18) 6 9599 LISTS.UFL.EDU (Linux 2.6.32) 7 8931 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 8 8362 MARIST (VM/SP 2.0) 9 8079 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 10 7213 LISTSERV.LIV.AC.UK (Linux 2.6.32) 11 6703 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 12 6081 LISTSERV.UGA.EDU (Linux 2.6.32) 13 5467 LISTS.UMN.EDU (Linux 2.6.32) 14 5050 LISTSERV.TAMU.EDU (Linux 3.0.101) 15 4845 LS.KULEUVEN.BE (Linux 2.6.32) 16 4372 LISTSERV.UTORONTO.CA (Linux 3.10.0) 17 4186 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 4053 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 4026 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 20 3998 LISTS.QUEENSU.CA (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 736557 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 502494 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 475567 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 4 384763 LISTS.PSU.EDU (AIX 6.1) 5 295405 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 283351 LISTES.ULAVAL.CA (Linux 3.10.0) 7 221089 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-957.12.2.el7.x86_64) 8 208467 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 9 206074 LISTSERV.UGA.EDU (Linux 2.6.32) 10 188350 LISTS.HAWAII.EDU (Linux 2.6.32-754.23.1.el6.x86_64) 11 188204 LISTS.UFL.EDU (Linux 2.6.32) 12 183578 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 13 180929 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 14 177773 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 15 153920 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 16 151927 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 17 133652 LISTSERV.UA.EDU (Linux 4.12.14) 18 124822 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 123593 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 20 121918 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 300656 COMPUTING@LIST.MSU.EDU (Linux 3.10.0) 2 59406 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 3 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 4 43782 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 5 41763 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 6 37518 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 28311 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 13 27977 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 24766 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 20 24455 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)