The usefulness of the patch in pkp/pkp-lib#1723: force_default_envelope_sender moves the traditional from to a reply-to for DMARC compliance by ctgraham · Pull Request #1724 · pkp/pkp-lib · GitHub will depend largely on what exactly is preventing the mail delivery. @asmecher’s suggestion is a good start for seeing if other mail sent natively from the server gets delivered.
There are several considerations in validating email, including SPF, DMARC, and DKIM. The relationships of these standards to OJS is discussed a bit here:
The best way to troubleshoot email problems is digging into the SMTP logs (which you may not have easy access to) and the SMTP headers (which are hidden within every email you receive). On testing solution I’ve used in the past is to email something to a mailinator.com address, which is very permissive for receiving messages and which allows you to see the SMTP headers for the message. Within these headers, look for failure messages for SPF and/or DMARC, and look for a valid DKIM signature.