When the mail server has turned off legacy mail protocols -- IMAP, POP3,
ManageSieve and sending from mail apps -- for this account, whether for
the whole server or for the account's organization, Settings › Security
says so at the top of App passwords, the section people come to when a
phone won't connect:
Your organization allows only {app} and JMAP apps, so phone and desktop
mail apps can't connect to this account.
This is INBUXA's legacy-protocols LP-19. The server reports it per
account as legacyProtocols on the urn:inbuxa:jmap account capability
(contract C-1); anything short of a plain "disabled" -- an older server,
another server, no session yet -- reads as on, so the line never appears
where it isn't true.
The app's name comes from {app}, as everywhere else. Translated into all
nine languages, in the register each catalog already uses.
jcoffey-dev