![[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 754143 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 668726 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 431648 LISTS.PSU.EDU (AIX 6.1) 4 422804 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 5 255827 LIST.UNM.EDU (Linux 2.6.32-754.30.2.el6.x86_64) 6 247966 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 7 246132 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 8 241181 LISTSERV.UGA.EDU (Linux 2.6.32) 9 231974 LISTS.HAWAII.EDU (Linux 2.6.32-754.33.1.el6.x86_64) 10 228664 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1127.13.1.el7.x86_64) 11 224433 LISTS.UFL.EDU (Linux 2.6.32) 12 220524 LISTES.ULAVAL.CA (Linux 3.10.0) 13 210659 LISTSERV.LIV.AC.UK (Linux 2.6.32) 14 188919 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 15 185715 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 16 184606 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 17 176950 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 18 172399 LISTSERV.ACM.ORG (Windows Server 2012 R2 Datacenter x64 Edition) 19 160366 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 20 148786 LISTSERV.UA.EDU (Linux 4.12.14)
Pos Subscribers Site --- ----------- ---- 1 5188324 LISTES.ULAVAL.CA (Linux 3.10.0) 2 4847976 LISTS.PSU.EDU (AIX 6.1) 3 2163298 LS.KULEUVEN.BE (Linux 2.6.32) 4 1720521 LISTSERV.UGA.EDU (Linux 2.6.32) 5 1540004 LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 1361002 LISTS.WAYNE.EDU (Linux 2.6.32) 7 1217494 LISTSERV.UTORONTO.CA (Linux 3.10.0) 8 1193228 LISTSERV.TAMU.EDU (Linux 3.0.101) 9 1127742 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 10 1099685 LIST.MSU.EDU (Linux 3.10.0) 11 1059036 LISTS.UFL.EDU (Linux 2.6.32) 12 957319 LISTS.UMN.EDU (Linux 3.10.0) 13 923460 LISTSERV.UA.EDU (Linux 4.12.14) 14 913210 LISTSERV.ECU.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 15 858913 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 16 846826 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 839097 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 823390 LISTSERV.UH.EDU (Linux 3.10.0) 19 814426 LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 20 805304 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition)
Pos Lists Site --- ----- ---- 1 34750 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16569 LISTS.PSU.EDU (AIX 6.1) 3 14245 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 7468 LISTSERV.LIV.AC.UK (Linux 2.6.32) 8 6733 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6401 LISTSERV.UGA.EDU (Linux 2.6.32) 10 5701 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 11 5482 LISTSERV.UTORONTO.CA (Linux 3.10.0) 12 5141 LS.KULEUVEN.BE (Linux 2.6.32) 13 5025 LISTSERV.TAMU.EDU (Linux 3.0.101) 14 4896 LISTS.UMN.EDU (Linux 3.10.0) 15 4197 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 4196 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 17 4165 LISTS.QUEENSU.CA (Linux 3.10.0) 18 3841 LISTSERV.MILLERSVILLE.EDU (Linux 2.6.32) 19 3718 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 20 3316 LISTSERV.BROWN.EDU (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 725730 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 668209 LISTSERV.TAMU.EDU (Linux 3.0.101) 3 428542 LISTS.PSU.EDU (AIX 6.1) 4 421725 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 5 255601 LIST.UNM.EDU (Linux 2.6.32-754.30.2.el6.x86_64) 6 243293 LISTSERV.BUFFALO.EDU (Linux 3.10.0) 7 236965 LISTSERV.UGA.EDU (Linux 2.6.32) 8 230143 LISTS.HAWAII.EDU (Linux 2.6.32-754.33.1.el6.x86_64) 9 228460 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1127.13.1.el7.x86_64) 10 222992 LISTS.UFL.EDU (Linux 2.6.32) 11 220293 LISTES.ULAVAL.CA (Linux 3.10.0) 12 203391 LISTSERV.LIV.AC.UK (Linux 2.6.32) 13 183310 LISTSERV.UCONN.EDU (Windows Server 2012 R2 Standard x64 Edition) 14 183264 LSV.UKY.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 15 177272 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 16 176729 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 17 166232 LISTSERV.SYR.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 157984 LISTSERV.REDIRIS.ES (Linux 2.6.32-504.3.3.el6.x86_64) 19 145532 LISTSERV.UA.EDU (Linux 4.12.14) 20 140032 LISTSERV.AAP.ORG (Windows Server 2012 R2 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 59318 CAREERCENTERUPDATE@LISTSERV.UGA.EDU (Linux 2.6.32) 2 54050 AMIS-CNRS-INTERNATIONAL-L@IN2P3.FR (Linux 3.10.0) 3 42938 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2012 R2 Datacenter x64 Edition) 4 41802 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 5 36438 CMU-BASKETBALL@LS2.CMICH.EDU (Linux 3.10.0) 6 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 7 33596 L-SMEAL-REPORT@LISTS.PSU.EDU (AIX 6.1) 8 30835 FOCIS_GROUP@LISTS.WAYNE.EDU (Linux 2.6.32) 9 28918 BEDRIJVENLIJST@LS.KULEUVEN.BE (Linux 2.6.32) 10 28918 BEDRIJVENLIJST2@LS.KULEUVEN.BE (Linux 2.6.32) 11 28309 L-THON-NEWS@LISTS.PSU.EDU (AIX 6.1) 12 27708 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 13 27517 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Linux 2.6.32) 14 27390 VOLUPDATE@LISTSERV.UTK.EDU (Solaris 2.10) 15 26418 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 16 25574 ISMA@LS.KULEUVEN.BE (Linux 2.6.32) 17 25009 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 24343 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 20 23332 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0)