Re: [Evolution] IMAP - Junk and Trash folder appear twice

[Pete Biggs <pete biggs org uk>]

> > With a real trash the message is actually moved to the folder when it
> > is deleted and it disappears completely from the original folder.
>                      ^^^^^^ 
> Can we be sure about that or how it's programmed ? For all I know IMAP
> specification has neither a MOVE nor a DELETE command for single
> messages. Can you go into detail how a standard IMAP server would do
> this move or post a point of knowledge ?

The MOVE command is an IMAP extension detailed in RFC6851

  https://tools.ietf.org/html/rfc6851

How the server implements it is unimportant so long as it appears as a
single operation to the client.  If Evo sees the "MOVE" command as an
extension reported in the CAPABILITIES directive, then it will use it,
otherwise it falls back to COPY+DELETE.

Modern servers fall into two categories really: database driven or
Maildir backed.  With both these a MOVE is trivial: with a database you
just change the record in the database so that the message appears to
be elsewhere in IMAP; and with Maildir it is just a single filesystem
atomic 'mv' command (well, it's done through system commands, but just
amounts to moving the inode reference in the directory entries - no
bytes are actually moved!).

P.