Stefan Bauer skrev den 2019-06-16 17:46:
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
cyrus-sasl support rimap, if o365 users can use that ?if not it would not stop you from make own sasl auth backends for custommers, but try rimap first