A customer can receive a reply from the team address while other staff cannot find it in the shared mailbox. They may then answer the same enquiry again. Check where sent copies are stored before assuming the original reply failed.

Microsoft documents that, by default, mail sent from a shared mailbox is saved in the sender’s own Sent Items rather than the shared mailbox’s Sent Items. This is a visibility problem for the team, separate from permission to send the message.

Confirm the present behaviour

Choose a harmless, already-approved example and compare the sender’s Sent Items with the shared mailbox’s Sent Items. Check the actual From address and recipient. A message sent from the person’s own mailbox is not a valid test of the shared-address workflow.

An authorised administrator can open Teams & groups, Shared mailboxes in the Microsoft 365 admin center, select the mailbox and edit Sent items. Choose the options appropriate to the team’s sending method, and record the previous setting before changing it.

Test with two members

Have one authorised team member send a reviewed test message using the shared identity. Have a second member, signed in as themselves, find that exact message in the shared Sent Items and inspect its contents. Repeat for any different sending method the team actually uses, rather than assuming one successful client test covers everything.

Do not assume a new setting will reconstruct older sent-mail history. Agree where staff should look for earlier replies and whether any historical record needs a separate, authorised consolidation.

A visible sent copy helps colleagues understand what was promised, but it does not assign an owner to an enquiry. Agree on a simple rule for who is handling each open conversation and when it is complete.

Record the tested accounts, sending method and observed copy location in the mailbox handover notes. That makes a later “did we answer this?” question much easier to resolve.

References: Shared mailbox Sent Items settings.