The imapclient needs more changes, like more strict parsing, before it can be a
generally usable IMAP client, these are a few steps towards that.
- Fix a bug in the imapserver METADATA responses for TOOMANY and MAXSIZE.
- Split low-level IMAP protocol handling (new Proto type) from the higher-level
client command handling (existing Conn type). The idea is that some simple
uses of IMAP can get by with just using these commands, while more intricate
uses of IMAP (like a synchronizing client that needs to talk to all kinds of
servers with different behaviours and implemented extensions) can write custom
commands and read untagged responses or command completion results
explicitly. The lower-level method names have clearer names now, like
ReadResponse instead of Response.
- Merge the untagged responses and (command completion) "Result" into a new
type Response. Makes function signatures simpler. And make Response implement
the error interface, and change command methods to return the Response as error
if the result is NO or BAD. Simplifies error handling, and still provides the
option to continue after a NO or BAD.
- Add UIDSearch/MSNSearch commands, with a custom "search program", so mostly
to indicate these commands exist.
- More complete coverage of types for response codes, for easier handling.
- Automatically handle any ENABLED or CAPABILITY untagged response or response
code for IMAP command methods on type Conn.
- Make difference between MSN vs UID versions of
FETCH/STORE/SEARCH/COPY/MOVE/REPLACE commands more clear. The original MSN
commands now have MSN prefixed to their name, so they are grouped together in
the documentation.
- Document which capabilities are needed for a command.
Once clients enable this extension, commands can no longer refer to "message
sequence numbers" (MSNs), but can only refer to messages with UIDs. This means
both sides no longer have to carefully keep their sequence numbers in sync
(error-prone), and don't have to keep track of a mapping of sequence numbers to
UIDs (saves resources).
With UIDONLY enabled, all FETCH responses are replaced with UIDFETCH response.
Keeping the message files around, and the message details in the database, is
useful for IMAP sessions that haven't seen/processed the removal of a message
yet and try to fetch it. Before, we would return errors. Similarly, a session
that has a mailbox selected that is removed can (at least in theory) still read
messages.
The mechanics to do this need keeping removed mailboxes around too. JMAP needs
that anyway, so we now keep modseq/createseq/expunged history for mailboxes
too. And while we're at it, for annotations as well.
For future JMAP support, we now also keep the mailbox parent id around for a
mailbox, with an upgrade step to set the field for existing mailboxes and
fixing up potential missing parents (which could possibly have happened in an
obscure corner case that I doubt anyone ran into).
an é (e with accent) can also be written as e+\u0301. the first form is NFC,
the second NFD. when logging in, we transform usernames (email addresses) to
NFC. so both forms will be accepted. if a client is using NFD, they can log
in too.
for passwords, we apply the PRECIS "opaquestring", which (despite the name)
transforms the value too: unicode spaces are replaced with ascii spaces. the
string is also normalized to NFC. PRECIS may reject confusing passwords when
you set a password.
so a single user cannot fill up the disk.
by default, there is (still) no limit. a default can be set in the config file
for all accounts, and a per-account max size can be set that would override any
global setting.
this does not take into account disk usage of the index database. and also not
of any file system overhead.
before, we used heuristics to decide when to train/untrain a message as junk or
nonjunk: the message had to be seen, be in certain mailboxes. then if a message
was marked as junk, it was junk. and otherwise it was nonjunk. this wasn't good
enough: you may want to keep some messages around as neither junk or nonjunk.
and that wasn't possible.
ideally, we would just look at the imap $Junk and $NotJunk flags. the problem
is that mail clients don't set these flags, or don't make it easy. thunderbird
can set the flags based on its own bayesian filter. it has a shortcut for
marking Junk and moving it to the junk folder (good), but the counterpart of
notjunk only marks a message as notjunk without showing in the UI that it was
marked as notjunk. there is also no "move and mark as notjunk" mechanism. e.g.
"archive" does not mark a message as notjunk. ios mail and mutt don't appear to
have any way to see or change the $Junk and $NotJunk flags.
what email clients do have is the ability to move messages to other
mailboxes/folders. so mox now has a mechanism that allows you to configure
mailboxes that automatically set $Junk or $NotJunk (or clear both) when a
message is moved/copied/delivered to that folder. e.g. a mailbox called junk or
spam or rejects marks its messags as junk. inbox, postmaster, dmarc, tlsrpt,
neutral* mark their messages as neither junk or notjunk. other folders mark
their messages as notjunk. e.g. list/*, archive. this functionality is
optional, but enabled with the quickstart and for new accounts.
also, mox now keeps track of the previous training of a message and will only
untrain/train if needed. before, there probably have been duplicate or missing
(un)trainings.
this also includes a new subcommand "retrain" to recreate the junkfilter for an
account. you should run it after updating to this version. and you should
probably also modify your account config to include the AutomaticJunkFlags.
