![[LISTSERV - the mailing list management classic]](/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 199100 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 2 189029 LISTSERV.LIV.AC.UK (Linux 3.10.0) 3 132329 LISTS.PORTSIDE.ORG (Linux 4.9.0-19-amd64) 4 102299 LISTSERV.BROWN.EDU (Linux 3.10.0) 5 88949 YORKU.CA (Linux 4.15.0) 6 64444 LISTSERV.ICORS.ORG (Windows Server 2022 Standard x64 Edition) 7 53892 LIST.PM.GC.CA (Windows Server 2016 Datacenter x64 Edition) 8 47456 LISTS.HAWAII.EDU (Linux 3.10.0-1160.118.1.el7.x86_64) 9 43452 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 10 37619 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 11 35241 LISTSERV.UGA.EDU (Windows Server 2019 Datacenter x64 Edition) 12 32585 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 13 29670 LISTSERV.GOARCH.ORG (Windows Server 2019 Datacenter x64 Edition) 14 26756 LIST.UVM.EDU (Linux 4.18.0) 15 26125 LISTS.PSU.EDU (Linux 3.10.0) 16 25565 MAILLISTS.READING.AC.UK (Windows Server 2019 Datacenter x64 Edition) 17 24850 LISTS.CLEMSON.EDU (Linux 4.19.288) 18 20485 LISTS.UFL.EDU (Linux 2.6.32) 19 20269 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 20 19567 LISTS.UMN.EDU (Linux 3.10.0)
Pos Subscribers Site --- ----------- ---- 1 5519780 LISTS.PSU.EDU (Linux 3.10.0) 2 4808842 LISTES.ULAVAL.CA (Linux 3.10.0) 3 1980333 LISTSERV.UGA.EDU (Windows Server 2019 Datacenter x64 Edition) 4 1777535 LISTSERV.TAU.AC.IL (Linux 2.6.9) 5 1400531 LISTSERV.UTORONTO.CA (Linux 3.10.0) 6 1124217 LISTSERV.TAMU.EDU (Linux 3.10.0) 7 1114171 LISTSERV.UA.EDU (Linux 4.12.14) 8 1077678 LISTS.WAYNE.EDU (Linux 3.10.0) 9 1069912 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 10 1059036 LISTS.UFL.EDU (Linux 2.6.32) 11 937073 LISTS.UMN.EDU (Linux 3.10.0) 12 931368 LIST.MSU.EDU (Linux 3.10.0) 13 902600 LISTSERV.UH.EDU (Linux 3.10.0) 14 898139 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 15 853488 LISTSERV.UTA.EDU (Windows Server 2016 Datacenter x64 Edition) 16 841887 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 17 778192 LISTSERV.ECU.EDU (Windows Server 2016 Standard x64 Edition) 18 710796 LISTS.QUEENSU.CA (Linux 6.2.0) 19 709328 LISTSERV.LIV.AC.UK (Linux 3.10.0) 20 667435 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition)
Pos Lists Site --- ----- ---- 1 28576 LISTES.ULAVAL.CA (Linux 3.10.0) 2 16900 LISTS.PSU.EDU (Linux 3.10.0) 3 14174 LISTSERV.TAU.AC.IL (Linux 2.6.9) 4 9788 LISTS.CLEMSON.EDU (Linux 4.19.288) 5 9599 LISTS.UFL.EDU (Linux 2.6.32) 6 8079 LISTSERV.TECHNION.AC.IL (Linux 4.18.0) 7 7203 LISTSERV.LIV.AC.UK (Linux 3.10.0) 8 6802 LISTSERV.MIAMIOH.EDU (Windows Server 2016 Standard x64 Edition) 9 6588 LISTSERV.UTORONTO.CA (Linux 3.10.0) 10 5568 LISTSERV.UGA.EDU (Windows Server 2019 Datacenter x64 Edition) 11 4965 LISTSERV.TAMU.EDU (Linux 3.10.0) 12 4872 LISTS.UMN.EDU (Linux 3.10.0) 13 4538 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 14 4401 LSV.UKY.EDU (Windows Server 2019 Datacenter x64 Edition) 15 3942 LISTS.QUEENSU.CA (Linux 6.2.0) 16 3614 LIST.UVM.EDU (Linux 4.18.0) 17 3586 LISTSERV.BROWN.EDU (Linux 3.10.0) 18 3343 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 19 2816 LISTSERV.KENT.EDU (Windows Server 2012 R2 Standard x64 Edition) 20 2776 LISTS.WAYNE.EDU (Linux 3.10.0)
Pos Recipients Site --- ---------- ---- 1 179543 LISTSERV.LIV.AC.UK (Linux 3.10.0) 2 159786 JISCMAIL.AC.UK (Windows Server 2019 Standard x64 Edition) 3 132315 LISTS.PORTSIDE.ORG (Linux 4.9.0-19-amd64) 4 92744 LISTSERV.BROWN.EDU (Linux 3.10.0) 5 88859 YORKU.CA (Linux 4.15.0) 6 63251 LISTSERV.ICORS.ORG (Windows Server 2022 Standard x64 Edition) 7 53970 LIST.PM.GC.CA (Windows Server 2016 Datacenter x64 Edition) 8 47421 LISTS.HAWAII.EDU (Linux 3.10.0-1160.118.1.el7.x86_64) 9 41765 LISTSERV.DARTMOUTH.EDU (Windows Server 2016 Datacenter x64 Edition) 10 33605 LISTSERV.UGA.EDU (Windows Server 2019 Datacenter x64 Edition) 11 32367 LISTSERV.SYR.EDU (Windows Server 2019 Standard x64 Edition) 12 30137 LISTSERV.NODAK.EDU (Windows Server 2019 Standard x64 Edition) 13 29506 LISTSERV.GOARCH.ORG (Windows Server 2019 Datacenter x64 Edition) 14 25743 LIST.UVM.EDU (Linux 4.18.0) 15 24821 LISTS.CLEMSON.EDU (Linux 4.19.288) 16 23233 LISTS.PSU.EDU (Linux 3.10.0) 17 20058 LIST.ETSI.ORG (Windows Server 2016 Datacenter x64 Edition) 18 19818 LISTS.UFL.EDU (Linux 2.6.32) 19 19744 MAILLISTS.READING.AC.UK (Windows Server 2019 Datacenter x64 Edition) 20 16936 LISTS.PURDUE.EDU (Windows Server 2019 Standard x64 Edition)
Pos Subscribers Site --- ----------- ---- 1 43113 SAFETYNOTICE@LISTSERV.UC.EDU (Windows Server 2019 Datacenter x64 Edition) 2 41833 OPSWNEWS@LISTSERV.NYSED.GOV (Linux 4.12.14) 3 40477 SUCCESS@LISTSERV.UGA.EDU (Windows Server 2019 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 30176 UG2021FALL@LISTSERV.UGA.EDU (Windows Server 2019 Datacenter x64 Edition) 7 29656 HALLCOLIBRARY-L@LISTSERV.UGA.EDU (Windows Server 2019 Datacenter x64 Edition) 8 28887 TAU-INNOVTL-ALL-STUDENTS@LISTSERV.TAU.AC.IL (Linux 2.6.9) 9 28249 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 26422 PARENTS@LISTSERV.TAMU.EDU (Linux 3.10.0) 15 25619 ECF-MIWD@NYED.USCOURTS.GOV (Linux 3.10.0) 16 24992 NCHPAD-NEWS@LISTSERV.UAB.EDU (Linux 3.10.0) 17 24290 DSSAT@LISTSERV.UGA.EDU (Windows Server 2019 Datacenter x64 Edition) 18 24288 EXCEL@LISTSERV.UTA.EDU (Windows Server 2016 Datacenter x64 Edition) 19 22768 STUDENT-TRAVEL-SURVEY-L@LISTSERV.OKSTATE.EDU (Windows Server 2019 Datacenter x64 Edition) 20 22300 L-AGSCINEWS@LISTS.PSU.EDU (Linux 3.10.0)