If a time value doesn't need to be sent to another host, saved to the db or otherwise used across
program restarts, a monotonically nondecreasing clock (`Instant`) should be used. But as `Instant`
may use `libc::clock_gettime(CLOCK_MONOTONIC)`, e.g. on Android, and does not advance while being in
deep sleep mode, get rid of `Instant` in favor of using `SystemTime`, but add `tools::Time` as an
alias for it with the appropriate comment so that it's clear why `Instant` isn't used in those
places and to protect from unwanted usages of `Instant` in the future. Also this can help to switch
to another clock impl if we find any.
a27e84ad89 "fix: Delete received outgoing messages from SMTP queue"
can break sending messages sent as several SMTP messages because they have a lot of recipients:
`pub(crate) const DEFAULT_MAX_SMTP_RCPT_TO: usize = 50;`
We should not cancel sending if it is such a message and we received BCC-self because it does not
mean the other part was sent successfully. For this, split such messages into separate jobs in the
`smtp` table so that only a job containing BCC-self is canceled from `receive_imf_inner()`. Although
this doesn't solve the initial problem with timed-out SMTP requests for such messages completely,
this enables fine-grained SMTP retries so we don't need to resend all SMTP messages if only some of
them failed to be sent.
* do not use ratelimiter for bots
i tried some other approaches as having optional ratelimiter
or handle `can_send()` for bots differently,
but all that results in _far_ more code and/or indirections -
esp. as the "bot" config can change and is also persisted -
and the ratelimiter is created
at a point where the database is not yet available ...
of course, all that could be refactored as well,
but this two-liner also does the job :)
* update CHANGELOG
New ratelimiter module counts number of sent messages and calculates
the time until more messages can be sent.
Rate limiter is currently applied only to MDNs. Other messages are
sent without rate limiting even if quota is exceeded, but MDNs are not
sent until ratelimiter allows sending again.
Switches from rusqlite to sqlx to have a fully async based interface
to sqlite.
Co-authored-by: B. Petersen <r10s@b44t.com>
Co-authored-by: Hocuri <hocuri@gmx.de>
Co-authored-by: link2xt <link2xt@testrun.org>
Previously MX records were queried only for OAuth 2 configuration and
did not affect the list of servers tried. User was required to manually
configure the servers for Google Workspace (former GSuite) domains.
Now MX records are queried during configuration. If provider is found in
offline database, its ID, corresponding to the filename, is saved as
`configured_provider`.
`configured_provider` is also set during database migration if email
address uses the domain from the provider database, but no MX querying
is done.
providers may have a maximum for the SMTP RCPT TO: header,
therefore, an outgoing message is split into several chunks.
the chunk size defaults to 50, however, if known to be larger or smaller
by a dedicated provider, this setting may be changed.
this does not affect the MIME To: headers,
if a provider has a maximum here, this is change would not help.
It was used when timeout was set on the whole smtp.send() operation.
Now only the operations inside smtp.send() can timeout, and such timeout
errors result in SendError, so SendTimeout is unused.
