Reviewing topics that ask about rate limiting / throttling digests and emails, the only available setting seems to be DISCOURSE_MAX_DIGESTS_ENQUEUED_PER_30_MINS_PER_SITE.
I don’t know if I should assume that the value for that is distributed exactly into an X-per-second rate.
And it’s only digests – I’d have to account for other surges like watching-first-post blasts, etc.
With the info I have, it doesn’t feel workable to use an SMTP service with a rate limit. Is there anything reassuring that I’ve missed?
The job that enqueues digests runs every 30 minutes, and all this setting does is put a maximum number of max_digests_enqueued_per_30_mins_per_site in the queue. It does not control how quickly the queue is processed.
BTW Seeing some pretty bad reviews for emailit recently, both on trustpilot and appsumo.
This will also ease the burden on your server since the relatively expensive operation of generating the email will only happen once, not over and over (if it gets rate limited).