> How would you whitelist things in your regular IMAP client?
If I were building it for my parents, I'd say "anything in Pending/Held/StrangerDanger that you flag will be whitelisted and will be in the Inbox from then on".
Flagging a message on iOS Mail is pretty straightforward - swipe+tap or long-press+tap+tap and easy enough conceptually as a "this is good" action, I think?
Backend picks up the flag change, adds the address to the inbox, strips the flag, and moves that message to the inbox.
Add "move it to junk to undo the whitelisting" for completion (also easy on iOS Mail).
Perhaps not as polished as writing a custom app to do it, no, but it seems fairly consumer friendly to me?
