Mail uses default sender address when reply-to field is left blank

Your software
My Mautic version is: 5.1.0
My PHP version is: 8.1.29
My Database type and version is: MariaDB 10

Your problem

Github Issue: Custom e-mail reply-to address uses default sender address when field is left blank #14040

When I send a Quick email or a Campaign email, and I do not set the “Reply to address”, it will use the system’s default mail address.

This is sample email:

The reply to address tooltip says: leave blank to use from address

When I use this in a simple campaign like this:

reply-to-campaign

When I receive this mail in Thunderbird the reply-to adress is the system’s default mail address:

(“Antwort an” == “Reply to”)

These errors are showing in the log: none

Steps I have tried to fix the problem: -