After subscribing a stream email address to a Mailman email list
and receiving a message from it (using the polling configuration
with an Exim + Dovecot mailserver), the following error message
is emitted by Zulip:
Logger zerver.lib.email_mirror, from module zerver.lib.email_mirror line 77:
Error generated by Anonymous user (not logged in) on zulip deployment
Sender: "Foo Bar" <foo@example.com>
To: No recipient found
Missing recipient in mirror email
This is because the To: header on the received email corresponds
to the email list, and there are no other headers to indicate the
final recipient, apart from the "Envelope-To" header added by
Exim. To resolve this problem, the commit adds "Envelope-To" to
the list of headers to check for a match.
type().__name__ is sufficient, and much readable than type(), so it's
better to use the former for keys.
We also make the classes consistent in forming the keys in the format
type(self).__name__:identifier and adjust logger.warning and statsd to
take advantage of that and simply log the key().
This is just a refactoring to the more modern API
for sending internal messages.
To make this work we now plumb the email_gateway
flag through `internal_send_stream_message` instead
of `internal_send_message`.
We also change `send_zulip` to have its callers
pass in a full UserProfile object (which one of
them already had).
If an email is sent with the .prefer-html option, but it has no html
body, it's better to fall back to plaintext content instead of treating
it as a user error.
Closes#13484.
These options tell zulip whether to prefer the plaintext or html version
of the email message. prefer-text is the default behavior, so including
the option doesn't change anything as of now, but we're adding it to
prepare to potentially change the default behavior in the future.
Fixes#13416
We used to search only one level in depth through the MIME structure,
and thus would miss attachments that were nested deeper (which can
happen with some email clients). We can take advantage of message.walk()
to iterate through each MIME part.
process_missed_message did nothing other than calling
send_to_missed_message_address with the same arguments, so there's no
reason to have these as separate functions.
Addresses point 1 of #13533.
MissedMessageEmailAddress objects get tied to the specific that was
missed by the user. A useful benefit of that is that email message sent
to that address will handle topic changes - if the message that was
missed gets its topic changed, the email response will get posted under
the new topic, while in the old model it would get posted under the
old topic, which could potentially be confusing.
Migrating redis data to this new model is a bit tricky, so the migration
code has comments explaining some of the compromises made there, and
test_migrations.py tests handling of the various possible cases that
could arise.
In addition to the "+show-sender" option, we now add "+include-footers"
which disables stripping of the footer from the email body if this token
is included in the email address.
To enable a comfortable way of adding more optional tokens in the
address (like current '+show-sender') we change decode_email_address to
return a general dictionary containing options specified through adding
these optional tokens in the To: address. For now, we only have
"+show-sender", but more can be easily added using this change.
log_and_report and its helper functions were mostly old code no longer
well adapted to how email mirror works currently, as well as having no
test coverage. We rewrite this part of the email to report errors in a
similar manner, and add tests for it. We're able to get rid of the
clunky and now useless debug_info dictionary in process message, as
log_and_report only needs the recipient email in its third argument.
The only place in which process_stream_message used debug_info was to
set the 'stream' key, which would only be used if ZulipEmailForwardError
was raised after this line in the code - which is impossible, because after
that line only send_zulip (which doesnt raise this exception) and
logger.info get called, then process_stream_message successfully returns
and then process_message succesfully returns as well. So this debug_info
code wasn't doing anything. We remove it.
If the text part of an email message didn't specify the charset in the
Content-Type header, the text content wouldn't be found. We fix this, by
assuming us-ascii charset in those cases, as specified by RFC6657:
https://tools.ietf.org/html/rfc6657
With the previous commit, fixes#1836.
As specified in the issue above, we make
get_email_gateway_message_string_from_address raise an exception if
it doesn't recognise the email gateway address pattern. Then, we make
appropriate adjustments in the codepaths which call this function.
These functions don't really belong in actions.py, so we move them out,
into email_mirror_helpers.py. They can't go directly into
email_mirror.py or we'd get circular imports resulting in ImportError.
Closes#2420
We add rate limiting (max X emails withing Y seconds per realm) to the
email mirror. By creating RateLimitedRealmMirror class, inheriting from
RateLimitedObject, and rate_limit_mirror_by_realm function, following a
mechanism used by rate_limit_user, we're able to have this
implementation mostly rely on the already existing, and proven over
time, rate_limiter.py code. The rules are configurable in settings.py in
RATE_LIMITING_MIRROR_REALM_RULES, analogically to RATE_LIMITING_RULES.
Rate limit verification happens in the MirrorWorker in
queue_processors.py. We don't rate limit missed message emails, as due
to using one time addresses, they're not a spam threat.
test_mirror_worker is adapted to the altered MirrorWorker code and a new
test - test_mirror_worker_rate_limiting is added in test_queue_worker.py
to provide coverage for these changes.
To prepare for changing how the stream name gets encoded into mirror
email addresses while making sure old addresses keep working, we ignore
the stream_name part when receiving emails into the mirror and we only
look at the email_token to identify into which stream to mirror the
email.
Addresses point 2 of #10612. We use a regex to detect if a form
of FWD indicator is present at the beginning of the subject, which
means the message has been forwarded.
remove_quotations argument is added to a couple of functions where
it's necessary.
In filter_footer, the criteria for a line to be a possible beginning
of a footer is changed to line.strip() == "--", instead of
line.strip().startswith("--"), because the former would remove
quotations from plaintext emails. This change makes sense, because
RFC 3676 specifies ""-- " as the separator line between the body
and the signature of a message":
https://tools.ietf.org/html/rfc3676
We remove the 'subject' argument of process_stream_message and make
subject processing happen inside the function, as it's a more
appropriate place than the general process_message function and is
needed to have a good way of disabling removing quotations in forwarded
emails sent into the mirror.
Fixes part 3 of #10612. When sending an email to the email mirror to a
stream address, if "+show-sender" is added in the address, the stream
message will now include "From: <sender>" at the top.
For internal stream messages, most of the time, we have access to
a Stream object. For the few corner cases where we don't, it is a
much cleaner approach to have a separate function that accepts a
stream name than having one multi-option helper that accepts both
names and objects.
If the caller has access to a Stream object, it is wasteful to
query a database for a stream by ID or name. In addition, not
having to go through stream names eliminates various classes of
possible bugs involved with re-fetching the Stream object by name.
Previously, we had some hand-written logic for parsing the subject
line of the email's headers and turning it into a Python string using
each of the valid encodings for an email. That logic was buggy, and
sometimes resulted in a bytes object being passed into the
`send_zulip`, which would eventually throw an exception.
The fix for this is to use the Python standard library make_header
method for handling internationalized email headers.
https://stackoverflow.com/questions/7331351/python-email-header-decoding-utf-8
Fixes part 1 of #10612. We use a regex to remove RE:, FWD: (and similar
variations) from email subjects. Unit test is included, we add
subjects.json in fixtures containing various subjects to try the
stripping on.
Anders Kaseorg
Udit107710
Emilio López
Mateusz Mandera
Steve Howell
Tim Abbott
Eeshan Garg
Anders Kaseorg