Mozilla connect is the best place to raise your ideas where the community can then vote for them. https://connect.mozilla.org/t5/ideas/idb-p/ideas/label-name/thunderbird%20android/tab/most-kudoed Maybe you can add some clarity on how you're getting to the position where "unundisclosed-recipients" is displayed. What are the two use cases your distinguishing between and what would you like to see displayed? The closest I could get to replicating this was by sending an email with recipient addresses placed only in the bcc field (blind copy). Nothing being entered in the "To" or "CC" fields. Looking at the same email in the sent items folder displayed unknown recipient.