Looking for a little advice here with regard to the optimum setup for a scenario in which I have a purely internal Discourse install (accessible only via intranet, to internal users) which will thus only ever need to send e-mail to the organization-internal domain…
…but that domain happens to be handled by Office 365.
I’ve seen the various posts regarding problems using O365 for Discourse installations (and reproduced many of them myself beforehand), and so I’m currently bouncing e-mails via Mailjet to get them where they need to go, but it really seems fairly ridiculous to have to involve a third-party mass-mailing service to send internal mail. Am I missing something obvious, or is this really the best way to go about it?
In a way, Office365 itself is a third-party mass-mailing service
Since Microsoft doesn’t really offer public SMTP service as part of those subscriptions (AFAICT), what we did in our case is set up MX records etc. for a subdomain and use that with (yes, yet another) 3rd-party SMTP service for outbound mail from Discourse. Email are also handled by this 3rd-party and notify Discourse via API/webhook.
You may have to have your O365 admin whitelist the new subdomain if you take this approach, so it doesn’t get caught in aggressive spam filters.
