https://bugs.koha-community.org/bugzilla3/show_bug.cgi?id=43340 Bug ID: 43340 Summary: Koha's SMTP connection rate can trigger errors Initiative type: --- Sponsorship --- status: Product: Koha Version: Main Hardware: All OS: All Status: NEW Severity: normal Priority: P5 - low Component: Notices Assignee: koha-bugs@lists.koha-community.org Reporter: kyle@bywatersolutions.com QA Contact: testopia@bugs.koha-community.org CC: martin.renvoize@openfifth.co.uk Target Milestone: --- When sending email, Koha creates a new SMTP connection for each message. Every single notice does a full connect: EHLO => STARTTLS => auth => send => quit A burst of notices means dozens of connections in seconds from one IP. In practice, this seems to trigger Goggole's Google's per-IP connection rate limiting, which responds with 421-4.7.0 at EHLO. Koha doesn't limit simultaneous connections. There's only ever one connection at a time (the cron is a single sequential process). The problem is connection rate, and Koha has no throttle, delay, or connection-reuse. -- You are receiving this mail because: You are watching all bug changes. You are the assignee for the bug.