ユーザーはメールで「あなたのアカウントには必要な信頼レベルがありません...」というエラーメッセージを受け取っています

[Moin]

@exlabs

I hope this use case can be supported some how?

I guess currently not

Category not accepting "anonymous email" from known users

Reproduce: Have a “private” category that only has create/reply/see access for members of a specific group. No other permissions. Enable “anonymous email in” for that specific via a unique working alias to the incoming POP account. Have a non-staff user that is not a member of the group send an email report in to the category email address from the email address associated with their account. Send in an email from an account not associated with any known Discourse account. Expected Behavior: …

But you can also publish the message from the group inbox to a category with the 'make public topic" option in the wrench menu.

So using a group inbox could be your workaround