Exim4 failts to use smtp.office365.com as its smarthost

[ael]

On Fri, Aug 04, 2023 at 07:29:18AM +0200, Sébastien Hinderer wrote:
> Here is the relevant excerpt from mainlog:
> 
> 2023-08-04 07:19:33 1qRnDp-002mcZ-0B <= mail at domain.org U=user P=local S=470 id=ZMyKZdvYD7a0zP8z at om.localdomain

Well, I am not sure what is going on in that log, but plain exim does not
support oauth which is needed to send to office365.

Until exim supports oauth natively, you need a helper like my
https://gitlab.com/clearfocus/oauth2_exim

ael