SMTP on EXCHANGE with anonymous login


We are trying to use ERPNext within our company. System is working fine, but we have a problem with sending emails.
We are using MS Exchange 2016 - IMAP is ok with login. BUT we are using SMTP with anonymous login.
(no possibility to change that).

So is there any way to tell ERPNext connect to SMTP ( on port 25 with TLS withour user/pass ?

ERPNext: v11.x.x-develop (0c3d345) (develop)
Frappe Framework: v11.x.x-develop (d38e5d5) (develop)

I am also using ERPNext at my own company with google apps and it’s working fine!