fetch BODYSTRUCTURE along with ENVELOPE from server and set
has_attachments based on the MIME structure of the envelope.
Notes: BODYSTRUCTURE returns the MIME structure of the envelope without
the data, so if it includes a multipart/mixed it *should* have
attachments.
ENVELOPE returns basic headers of the message like Sender, Subject, Date
etc.
Previous behaviour: connection with IDLE was stopped every 5 minutes to
poll the other threads. As a result messages received within that time
window when there was no IDLING were never received.
Current behaviour: polling is done in the main connection.
Add a boolean field to accounts that states if the account can be
accessed. Local backends (Maildir/mbox) return true every time, but
remote backends (IMAP) may not. Accounts start as offline and then get
initialised when their status goes to online. Right now if an IMAP
account startup but later get offline, there are crashes. With this
change the account can be switched back to offline when that happens.
Split the TlsStream of the live IMAP connection to an enum to allow both
offline and online states. The connection is restarted if offline when
requested.
Manos Pitsidianakis
Matthias Beyer