On 16 Jun2019, at 09:46, Stefan Bauer <cubew...@googlemail.com> wrote: > some of our users use o365 but would like to use our service for outgoing > mails. we are offering smtp sending services. integrating our service in o365 > is tricky, as one can only specify a smarthost but microsoft does not offer > any kind of authentication for smarthosts.
You can, and should (and I would say MUST) authenticate your users. You do not need Microsoft to authenticate them. > so i'm asking if someone also noticed that and can recommend best practice to > allow o365 to relay via postfix without available sasl authentication in a > secure way. Why would o365 be relaying via your server? User connects to your server. User authenticates and passes authentication User sends email Where is 0365 involved at all? —
