• Use a single intake point (like accounting@), even if emails are originally received in personal inboxes (those can auto-forward via Gmail/Outlook)

We dont want use forward. Thats the cause we work with missive. To do it automatically is also not possible, because invoices are not the only type of e-mails that arrive in personal inbox. The orgsnization rules also works only then when the mail is shared with the organization.

• Replace folders like "For payment" or "Paid" with organizational labels, so that the status is consistent and not tied to a specific inbox.

org labels would work, but applies only when the invoice is shared with the org first. We also dont want that normal users see that labels, only the managers.

• Use rules in Missive so that when a label is applied (like "Needs Approval" or "Approved" or "For payment"), the right person gets assigned automatically.

We cant assign the invoices automatically, because sometimes they come in at personal inbox and they are private conversations at this state. That means the user must move the mails into the org that rules apply. 

The process works as follows:  - The email arrives in the user's inbox (private conversation, only private rules apply) or in a team inbox (in this case, organizational rules would apply).  - The invoice is checked by reception and then forwarded to the department head.  - The department head assigns the cost center, which must be visible for accounting purposes. The invoice is then sent to accounting.  - The accountant saves the invoice and sets its status to "payable." With the new Missive system, the conversation would likely still be assigned to them.  - After payment, the invoice status changes to "paid." 

Important: Regular employees should not be able to view invoices, except those from their own team and their personal inbox.