How to make sure that mail for mail.ru does not fall into spam?

Question

Exim

Good day to all. Give advice on how and where to dig to solve such a problem:
We have 1C, from which mail is sent from one user to clients.
In order for these letters to be answered and answered by the specific manager
who sent them, the FROM FROM field is filled with the mailing address of this manager.
Those. one address is used for authorization and sending, and From is filled with another.
So mail.ru puts such letters in spam and not every client knows about the existence of
such a folder and not everyone has a desire to look there. If you send a letter that has
both From and Sender and envelope-from equal, then everything is OK. How it is possible to resolve it by means of EXIM?
Maybe someone came across and will help with practical advice.

Answer 1

Instead of spoofing the sender, use the return-path header.

Answer 2

to replace this heading in Exim? the return-path address must be different depending on who actually sends the letter. how to track?