If I knew what precise mechanism was used to send messages from Koha, I would happily look into the matter. The Koha system I help manage doesn't use a mail service that applies rate limits in this fashion, but my own work email runs on Microsoft 365, which does implement a limit of 30 messages per minute. I manage that system, and I have colleagues who run up against the limit from time to time. See https://learn.microsoft.com/en-us/office365/servicedescriptions/exchange-online-service-description/exchange-online-limits#sending-limits-1
So, if anyone out there is sending mail over M365, be aware that you could conceivably hit the limit if you have any event in Koha that will send many messages at once. Regards, David Liddle IT Manager david.lid...@wycliff.de (just not for this list) Wycliff e.V., https://wycliff.de Seminar für Sprache und Kultur, https://spracheundkultur.org Internationales Tagungszentrum Karimu, https://karimu.de _______________________________________________ Koha mailing list http://koha-community.org Koha@lists.katipo.co.nz Unsubscribe: https://lists.katipo.co.nz/mailman/listinfo/koha