1. When using maxage, local and remote messagelists are supposed to only
contain messages from at most maxage days ago. But local and remote used
different timezones to calculate what "maxage days ago" means, resulting
in removals on one side. Now, we ask the local folder for maxage days'
worth of mail, find the lowest UID, and then ask the remote folder for
all UID's starting with that lowest one.
2. maxage was fundamentally wrong in the IMAP-IMAP case: it assumed that
remote messages have UIDs in the same order as their local counterparts,
which could be false, e.g. when messages are copied in quick succession.
So, remove support for maxage in the IMAP-IMAP case.
3. Add startdate option for IMAP-IMAP syncs: use messages from the given
repository starting at startdate, and all messages from the other
repository. In the first sync, the other repository must be empty.
4. Allow maxage to be specified either as number of days to sync (as
previously) or as a fixed date.
Signed-off-by: Janna Martl <janna.martl109@gmail.com>
Signed-off-by: Nicolas Sebrecht <nicolas.s-dev@laposte.net>
