A message sent or scheduled from a shared or group identity lives in
that account. Undo send, "Edit" on a scheduled message and cancelling
one cancelled the submission in the right account (#874), but then
restored the message to Drafts, fetched and deleted it through the
login's primary account. That hit whichever primary message had the
same id - pulling an unrelated mail into Drafts or deleting it - and
left the unsent message sitting in the group's Sent.
`restoreEmailToDraft` now takes the account, and the store passes the
submission's account to restore, fetch and delete, using that
account's Drafts and Sent.
Linus Rath
9f11210b6a