our users send/receive via o365. the last mile o365->recipient should go through our service like o365->postfix->recipient
here, o365 does not offer smtp auth against postfix. Am Sonntag, 16. Juni 2019 schrieb @lbutlr <krem...@kreme.com>: > 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? > > > > > — > > >
