Unauthenticated email is not accepted due to domain's DMARC policy

Hmmm… It is true. But what changes concrete to do? To many messages on forums, to many explanation and just sajidakeel message gave me results.
In classic settings received error, for this>

[email]

; Use SMTP for sending mail instead of mail()
; smtp = On

; SMTP server settings
; smtp_server = mail.example.com
; smtp_port = 25

; Enable SMTP authentication
; Supported mechanisms: ssl, tls
; smtp_auth = ssl
; smtp_username = username
; smtp_password = password

Where to insert specific mail for all other editors? Earlier everything works very well. Now, on OJS 3.1.2 have problem with sending mails.

Regards,
Lazar