On my Mac, Mailspring almost always just spins at the top for Junk and Deteled emails, undercutting the ability to tell it to get rid of them. This has been so for as long as I remember. If it’s my installation, how can I fix it?
That spinner is the Empty trash now / Empty spam now button in the bar at the top of the Trash and Spam folders (How do I empty the trash / spam folder in Mailspring? — Mailspring Documentation). It turns into a spinner while an “empty folder” request for that account is still in Mailspring’s task queue, and goes back to a button once the mail server confirms the folder was emptied. If it spins forever, a previous “empty” request got stuck and never completed. Themes and plugins can’t cause it.
Two steps:
- Quit Mailspring completely (including the menu-bar icon) and relaunch — the sync engine retries pending tasks on startup, which clears it most of the time.
- If it’s still spinning after a relaunch, go to Preferences > General > Local Data > Reset Cache. That deletes the local database (which is where the stuck task lives) and re-syncs your accounts from the server; nothing is deleted from your mail account. Details here: Clearing the Mailspring cache — Mailspring Documentation
On the second question, that same bar is the bulk delete: it removes everything in the folder from the server in one go, so no plugin is needed.