How to view moved messages in your Sent and Draft folders
When viewing messages in your Sent or Drafts folders, you can choose whether to include sent messages and drafts that have been moved to a different folder (i.e. Archive, Spam, Trash).
By default, moved messages in the Sent and Drafts folders are hidden from view. To enable this feature:
1. Go to Settings → Go to settings → Proton Mail → Messages and composing → Messages → Keep messages in Sent/Drafts and toggle the switch on.