A plugin opens a message as a click on a list row or on a search result
entry naming one does, also a message of a shared or group account,
reached through the login that reads it. On the mail page it opens in
place, in the Pro shell in an email tab as a message link does there;
elsewhere the tab loads the message's link, at most five times a minute.
A message no login reads, or one its account does not have, is refused
with an error the plugin sees, as is one the mail page could not open.
Needs email:read.
Linus Rath
Jacob Zeitz