Otherwise Dovecot times out when trying to iterate over metadata
of the folder. Apparently it happens when attempting to delete
folder from the server over IMAP.
This change adds XDELTAPUSH capability.
Delta Chat clients detecting this capability
can set /private/devicetoken IMAP metadata
on the inbox to subscribe for Apple (APNS)
notifications.
Notifications are implemented in a new
`chatmail-metadata` service
which handles requests to set /private/devicetoken
IMAP metadata from Delta Chat clients
and /private/messagenew requests from
push_notification_lua script.
To avoid sending notifications for
MDNs, webxdc updates and Delta Chat sync messages,
messages with Auto-Submitted header are ignored
by setting $Auto keyword (flag) on them in Sieve script
and skipping such messages in push_notification_lua script.
Outgoing messages are also ignored.
I installed pyenv and then installed Python 3.9:
$ pyenv install 3.9
$ eval "$(pyenv init -)"
$ pyenv shell 3.9
In a clean repository I ran
$ scripts/cmdeploy init
$ scripts/cmdeploy run
$ scripts/cmdeploy dns
$ scripts/cmdeploy fmt
With the changes made all these commands work.
scripts/cmdeploy test fails some tests
using maildata fixture at
importlib.resources.files(__package__).joinpath("mail-data")
line but this is not critical.
ADSP RFC 5617 is declared historic because of no deployment:
<https://datatracker.ietf.org/doc/status-change-adsp-rfc5617-to-historic/>
However, it is declared as supported by <https://github.com/fastmail/authentication_milter>.
OpenDKIM has a release note from 2014-12-27 saying "Discontinue support for ADSP"
and does not support ADSP anymore.
Anyway, it does not hurt to publish a TXT record
indicating the strictest possible ADSP policy
that we apply to all incoming mail ourselves.
Unlike DMARC which allows either SPF or DKIM to pass,
ADSP requires that DKIM passes.
Testing that envelope FROM matches From: header
already happens in filtermail
and tested with `test_reject_forged_from`.
The most important part here is
`reject_sender_login_mismatch` check
documented in
<https://www.postfix.org/postconf.5.html#reject_sender_login_mismatch>.
OpenDKIM configuration
has two Lua scripts defining strict DKIM policy.
screen.lua filters out signatures that do not correspond
to the From: domain so they are not even checked.
final.lua rejects mail if it is not outgoing
and has no valid DKIM signatures.
OpenDKIM is configured as a milter on port 25 smtpd
to check DKIM signatures
and on mail reinjecting smtpd
to sign outgoing messages with DKIM signatures.
