![[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 595120 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 324561 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 288852 LISTS.PSU.EDU (Linux 3.10.0) 4 219701 LISTSERV.ACM.ORG (Windows Server 2016 Datacenter x64 Edition) 5 153566 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 6 150069 LISTES.ULAVAL.CA (Linux 3.10.0) 7 139866 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 8 138008 LISTS.HAWAII.EDU (Linux 3.10.0-1160.80.1.el7.x86_64) 9 132671 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 10 126371 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 11 125685 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 12 111092 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 13 111075 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 14 97280 LISTS.ROCHESTER.EDU (Windows Server 2012 R2 Standard x64 Edition) 15 90443 LISTSERV.UTORONTO.CA (Linux 3.10.0) 16 88481 LISTS.PORTSIDE.ORG (Linux 4.9.0-17-amd64) 17 87506 LISTSERV.WUSTL.EDU (Windows Server 2016 Standard x64 Edition) 18 82840 LISTS.UFL.EDU (Linux 2.6.32) 19 77381 LIST.MSU.EDU (Linux 3.10.0) 20 74406 LIST.UVM.EDU (Linux 2.6.32)
Pos Subscribers Site --- ----------- ---- 1 5588443 LISTES.ULAVAL.CA (Linux 3.10.0) 2 5427629 LISTS.PSU.EDU (Linux 3.10.0) 3 1955805 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1619360 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1118335 LISTSERV.UH.EDU (Linux 3.10.0) 7 1113233 LISTSERV.UA.EDU (Linux 4.12.14) 8 1087462 LISTS.WAYNE.EDU (Linux 2.6.32) 9 1086791 LISTSERV.TAMU.EDU (Linux 3.0.101) 10 1060904 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 11 1059036 LISTS.UFL.EDU (Linux 2.6.32) 12 946760 LIST.MSU.EDU (Linux 3.10.0) 13 937156 LISTS.UMN.EDU (Linux 3.10.0) 14 904099 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 15 853488 LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 16 833046 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 781289 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 18 709882 LISTSERV.LIV.AC.UK (Linux 3.10.0) 19 709620 LISTS.QUEENSU.CA (Linux 3.10.0) 20 692217 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
Pos Lists Site --- ----- ---- 1 35309 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16797 LISTS.PSU.EDU (Linux 3.10.0) 3 14174 LISTSERV.TAU.AC.IL (Linux 2.6.9) 4 10895 LISTSERV.UH.EDU (Linux 3.10.0) 5 9788 LISTS.CLEMSON.EDU (Linux 2.6.18) 6 9599 LISTS.UFL.EDU (Linux 2.6.32) 7 8079 LISTSERV.TECHNION.AC.IL (Linux 2.6.32) 8 7224 LISTSERV.LIV.AC.UK (Linux 3.10.0) 9 6791 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 10 6529 LISTSERV.UTORONTO.CA (Linux 3.10.0) 11 5482 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 12 4973 LISTSERV.TAMU.EDU (Linux 3.0.101) 13 4837 LISTS.UMN.EDU (Linux 3.10.0) 14 4537 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 15 4381 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 16 3924 LISTS.QUEENSU.CA (Linux 3.10.0) 17 3583 LIST.UVM.EDU (Linux 2.6.32) 18 3552 LISTSERV.BROWN.EDU (Linux 3.10.0) 19 3338 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 20 2825 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition)
Pos Recipients Site --- ---------- ---- 1 567451 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 317086 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 286205 LISTS.PSU.EDU (Linux 3.10.0) 4 149911 LISTES.ULAVAL.CA (Linux 3.10.0) 5 139583 LISTSERV.UCONN.EDU (Windows Server 2019 Datacenter x64 Edition) 6 136364 LISTS.HAWAII.EDU (Linux 3.10.0-1160.80.1.el7.x86_64) 7 129865 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 8 125506 LISTSERV.UIC.EDU (Linux 2.6.32-504.8.1.el6.x86_64) 9 123385 LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 10 110816 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 11 110629 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 12 108430 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 13 90563 LISTSERV.UTORONTO.CA (Linux 3.10.0) 14 88468 LISTS.PORTSIDE.ORG (Linux 4.9.0-17-amd64) 15 81643 LISTS.UFL.EDU (Linux 2.6.32) 16 76802 LIST.MSU.EDU (Linux 3.10.0) 17 73054 LIST.UVM.EDU (Linux 2.6.32) 18 72700 DISCUSSIONS.EQ.EDU.AU (Linux 3.10.0-1160.59.1.el7.x86_64) 19 67981 LISTS.WAYNE.EDU (Linux 2.6.32) 20 64665 LISTS.UMN.EDU (Linux 3.10.0)
Pos Subscribers Site --- ----------- ---- 1 42543 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 2 41830 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 3 40480 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 4 34587 TCUATHLETICSDIRECTOR@LISTSERV.TCU.EDU (Windows Server 2012 R2 Standard x64 Edition) 5 31621 TAU-STU-ACADEMICSEC-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 6 30181 UG2021FALL@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 7 29233 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 8 28887 TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 9 28253 L-THON-NEWS@LISTS.PSU.EDU (Linux 3.10.0) 10 27705 RECREATION@LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 11 27479 TAU4U@LISTSERV.TAU.AC.IL (Linux 2.6.9) 12 27372 VOLUPDATE@LISTSERV.UTK.EDU (Linux 3.10.0) 13 27346 UTENNSRP@LISTSERV.UTK.EDU (Linux 3.10.0) 14 26421 PARENTS@LISTSERV.TAMU.EDU (Linux 3.0.101) 15 25619 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0) 16 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 17 24288 EXCEL@LISTSERV.UTA.EDU (Windows Server 2008 R2 Enterprise x64 Edition) 18 23619 DSSAT@LISTSERV.UGA.EDU (Windows Server 2016 Datacenter x64 Edition) 19 22769 STUDENT-TRAVEL-SURVEY-L@LISTSERV.OKSTATE.EDU (Windows Server 2012 Datacenter x64 Edition) 20 22407 L-AGSCINEWS@LISTS.PSU.EDU (Linux 3.10.0)