![[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 590358 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 317809 LSERV.CARDSYS.AT (Linux 4.4.67-1-pve) 3 311301 LISTS.PSU.EDU (AIX 6.1) 4 223146 LISTSERV.TAMU.EDU (Linux 3.0.101) 5 199198 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 192222 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition + LSMTP V1.1b) 7 180885 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 8 180877 LISTSERV.BUFFALO.EDU (Solaris 2.11) 9 174152 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 170159 DIGITAL.ANNEXBUSINESSMEDIA.COM (Linux 3.13.0-32-generic) 11 167886 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 12 167801 LISTSERV.UMD.EDU (SunOS 5.10) 13 162182 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 142556 LISTSERV.UGA.EDU (Linux 2.6.32) 15 134422 LISTS.HAWAII.EDU (Linux 2.6.32-696.6.3.el6.x86_64) 16 132353 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 17 126457 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 18 122844 LISTSERV.UA.EDU (Linux 3.0.101) 19 121403 LISTS.UCDENVER.EDU (Windows Server 2012 R2 Standard x64 Edition) 20 116273 LISTS.UFL.EDU (Linux 2.6.18)
Pos Subscribers Site --- ----------- ---- 1 5282766 LISTS.PSU.EDU (AIX 6.1) 2 4186712 LISTES.ULAVAL.CA (Linux 2.6.18) 3 1929822 LS.KULEUVEN.BE (Linux 2.6.32) 4 1586936 LISTS.WAYNE.EDU (Linux 2.6.32) 5 1407622 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 6 1319971 LISTSERV.UGA.EDU (Linux 2.6.32) 7 1300414 LISTSERV.TAMU.EDU (Linux 3.0.101) 8 1293277 LISTSERV.TAU.AC.IL (Linux 2.6.9) 9 1185205 LISTSERV.UTORONTO.CA (Linux 2.6.18) 10 1059036 LISTS.UFL.EDU (Linux 2.6.18) 11 1011456 LISTS.UMN.EDU (Linux 2.6.32) 12 1009235 LISTSERV.BUFFALO.EDU (Solaris 2.11) 13 944029 LIST.MSU.EDU (Linux 3.0.34) 14 934700 LISTSERV.ND.EDU (Linux 2.6.18) 15 818258 CUVMC.AIS.COLUMBIA.EDU (VM/SP 4.0) 16 808737 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 17 784635 LISTSERV.UH.EDU (Linux 2.6.18) 18 767668 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 19 755003 LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition) 20 738565 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Lists Site --- ----- ---- 1 33630 LISTES.ULAVAL.CA (Linux 2.6.18) 2 16707 LISTS.PSU.EDU (AIX 6.1) 3 14011 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 4 13139 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 9788 LISTS.CLEMSON.EDU (Linux 2.6.18) 6 9599 LISTS.UFL.EDU (Linux 2.6.18) 7 7787 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 8 7254 MARIST (VM/SP 2.0) 9 6811 LISTSERV.TAMU.EDU (Linux 3.0.101) 10 6572 LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition) 11 6262 LISTSERV.LIV.AC.UK (Linux 2.6.32) 12 5704 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 13 5471 LISTS.UMN.EDU (Linux 2.6.32) 14 5165 LISTSERV.UGA.EDU (Linux 2.6.32) 15 4386 LISTSERV.NODAK.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 4340 LISTSERV.UTORONTO.CA (Linux 2.6.18) 17 4043 LS.KULEUVEN.BE (Linux 2.6.32) 18 3978 LISTSERV.ND.EDU (Linux 2.6.18) 19 3848 LISTS.QUEENSU.CA (Solaris 2.10) 20 3721 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Recipients Site --- ---------- ---- 1 566947 JISCMAIL.AC.UK (Windows Server 2008 R2 Enterprise x64 Edition) 2 306737 LISTS.PSU.EDU (AIX 6.1) 3 221298 LISTSERV.TAMU.EDU (Linux 3.0.101) 4 191649 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition + LSMTP V1.1b) 5 190219 LISTSERV.LIV.AC.UK (Linux 2.6.32) 6 178199 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 7 176428 LISTSERV.BUFFALO.EDU (Solaris 2.11) 8 171431 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 9 150181 LISTSERV.UMD.EDU (SunOS 5.10) 10 139117 LISTSERV.UGA.EDU (Linux 2.6.32) 11 133313 LISTS.HAWAII.EDU (Linux 2.6.32-696.6.3.el6.x86_64) 12 132012 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 13 126042 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 14 123859 LISTSERV.ICORS.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 15 121380 LISTS.UCDENVER.EDU (Windows Server 2012 R2 Standard x64 Edition) 16 117676 LISTSERV.UA.EDU (Linux 3.0.101) 17 114494 LISTS.UFL.EDU (Linux 2.6.18) 18 107680 LISTES.ULAVAL.CA (Linux 2.6.18) 19 107603 LIST.UVM.EDU (Linux 2.6.32) 20 107244 LISTS.UMN.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 300656 COMPUTING@LIST.MSU.EDU (Linux 3.0.34) 2 62485 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 3 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 4 41750 OPSWNEWS@LISTSERV.NYSED.GOV (AIX 7.1) 5 39677 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 6 36295 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 7 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 8 34346 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 9 33612 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 10 30848 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 11 29209 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 12 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 13 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 14 28346 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 15 27711 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2012 R2 Standard x64 Edition) 16 27415 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 17 26419 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 18 24990 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 2.6.32) 19 23805 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 20 23329 ECF-EDNY@NYED.USCOURTS.GOV (Linux 2.6.32)