So I submitted another patch, that now solves the problem and issues a proper ImproperConfiguration error instead of Attribute error.
First it checks the EMAIL_CONFIRMATION_FROM if that is not set than it checks for DEFAULT_FROM_EMAIL. If both are not configured than it issues a ImproperConfigurationError instead of the AttributeError, at least that helps in understanding that there is a problem in configuration and not the code.
I saw your patch, that's similar to one I had submitted initially but Florian pointed out that it is not the right way(https:/ /bugs.launchpad .net/postorius/ +bug/1437866/ comments/ 2)
So I submitted another patch, that now solves the problem and issues a proper ImproperConfigu ration error instead of Attribute error.
First it checks the EMAIL_CONFIRMAT ION_FROM if that is not set than it checks for DEFAULT_FROM_EMAIL. If both are not configured than it issues a ImproperConfigu rationError instead of the AttributeError, at least that helps in understanding that there is a problem in configuration and not the code.