Someone (not a user) sends a mail to a category address.
A moderator moves that message to another category.
He then replies.
The original sender receives a mail
The original sender replies
The original sender gets a notification with an error about the topic being locked or removed
What if you need to move an incoming mail to another category/department?
Solution: always accept discourse+{key}@domain.ext mails if the original topic exists and is not locked. Even when it is moved to another category. That way the conversation can continue.
Things to consider:
Should the new category be set to accept anonymous mails?
Does it matter if the new category has an incoming mail address or not?
If it has an incoming mail address, the new category will have a different address of course, will that be a problem?
Does this user have permission to reply in that category? Are you sure?
@zogstrip have we tested a simple topic rename / recategorize? I can’t think of any reason an email reply would be broken due to recategorize or rename between the time you read the topic and the time you reply to it via email.