Distinguish access from the sending role
Define who may read messages and who may send using the shared mailbox's identity. These can be separate permissions. In Microsoft 365, for example, full mailbox access does not automatically grant sending permission. Check the configured roles rather than assuming that seeing the folder means every function is available.
Use the intended individual sign-ins with delegated permissions. Passing around one password makes responsibility and later access removal harder to manage. Have the responsible administrator configure the arrangement, then check a new permission with an unimportant test message to a known address.
Make work status visible
Agree a few clear states, such as new, in progress and completed. Folders, categories or a suitable ticket system may represent them. A read marker is not a reliable completion signal because another person merely opening a message can change that state.
Decide how ownership of a message is shown and what happens during absence. If a colleague is preparing a response, someone covering the mailbox should not send a contradictory second reply. A short internal note about the next action may be sufficient, but make sure confidential internal notes are not accidentally included in the customer response.
Keep sent messages retrievable
Use a test message to establish where the sent copy appears and which sender address the recipient sees. The correct setting depends on the service and configuration. Without checking, a reply may remain only in the sender's personal folder even though the team later needs the conversation history.
Also define a shared filing route for completed correspondence and associated documents. Avoid a private parallel archive becoming the only record of a case. A colleague should be able to understand the history using the agreed common locations without needing access to somebody else's personal mailbox.
Review permissions against actual need
Revisit membership when roles change, temporary cover ends or someone leaves. Remove unnecessary permissions through the intended administration process. Record who maintains this list so short-term assistance does not accidentally become indefinite access.
Try the whole arrangement with a fictional enquiry: arrival, assignment, reply, completion and retrieval by a second person. That exercise can reveal a workflow whose technology functions correctly but whose status still depends too heavily on one colleague's memory. Adjust the shared procedure before applying it to a large queue of real messages.
