When a company uses Google Mail with their own domain, does Delta Chat detect this and use OAuth for login?
I think when it does not, it would require the user to allow “insecure” authentication, alarming users that delta chat is insecure. It does not matter if password authentication is secure or not, it is a marketing problem for delta when the user needs to set a checkmark for “insecure” apps.
Even when the user understands that there is no too big risk, it is harder to explain to them where to find the needed settings before “sign up”.
I want to recommend delta chat to a mid-size company, in that the employees look for a GDPR compliant messing solution, that will not get them into trouble because of non-EU servers.