[RFC-5322 allows](https://tools.ietf.org/html/rfc5322#section-3.6.2)
multiple addresses in the From header.
Django's SMTP backend supports this, as a single comma-separated
string (*not* a list of strings like the recipient params):
from_email='one@example.com, two@example.com'
to=['one@example.com', 'two@example.com']
Both Mailgun and SparkPost support multiple From addresses
(and Postmark accepts them, though truncates to the first one
on their end). For compatibility with Django -- and because
Anymail attempts to support all ESP features -- Anymail now
allows multiple From addresses, too, for ESPs that support it.
Note: as a practical matter, deliverability with multiple
From addresses is pretty bad. (Google outright rejects them.)
This change also reworks Anymail's internal ParsedEmail object,
and approach to parsing addresses, for better consistency with
Django's SMTP backend and improved error messaging.
In particular, Django (and now Anymail) allows multiple email
addresses in a single recipient string:
to=['one@example.com', 'two@example.com, three@example.com']
len(to) == 2 # but there will be three recipients
Fixes#60
Only real problem is in json serialization tests:
Python 3.6 [changed][1] the json serialization
error message to use the object's class name
rather than its repr. E.g.:
"Decimal('19.99') is not JSON serializable"
becomes:
"Object of type 'Decimal' is not JSON serializable"
Update tests that looked for specific serialization
error message to just look for the word "Decimal"
instead. (Works with all Python versions.)
[1]: https://bugs.python.org/issue26623
* **Future breaking change:**
Rename all Anymail backends to just `EmailBackend`,
matching Django's naming convention.
(E.g., switch to "anymail.backends.mailgun.EmailBackend"
rather than "anymail.backends.mailgun.MailgunBackend".)
The old names still work, but will issue a DeprecationWarning
and will be removed in some future release.
(Apologies for this change; the old naming convention was
a holdover from Djrill, and I wanted consistency with
other Django EmailBackends before hitting 1.0.)
Fixes#49.
Drop `from __future__ import unicode_literals`;
it was there for Python 3.2 compatibility (which
Anymail doesn't support). Ensures tests use normal
strs in Python 2.x.
Convert readthedocs links for their .org -> .io migration for hosted projects
As per [their blog post of the 27th April](https://blog.readthedocs.com/securing-subdomains/) ‘Securing subdomains’:
> Starting today, Read the Docs will start hosting projects from subdomains on the domain readthedocs.io, instead of on readthedocs.org. This change addresses some security concerns around site cookies while hosting user generated data on the same domain as our dashboard.
Test Plan: Manually visited all the links I’ve modified.
* Create generic TestBackend that simply collects
send parameters
* Change BackendSettingsTests to TestBackend,
and add some missing cases
* Add UnsupportedFeatureTests
* Replace repetitive per-backend SEND_DEFAULTS
test cases with single (and more comprehensive)
SendDefaultsTests
* message.template_id to use ESP stored templates
* message.merge_data and merge_global_data
to supply per-recipient/global merge variables
(with or without an ESP stored template)
* When using per-recipient merge_data, tell ESP to use
batch send: individual message per "to" address.
(Mailgun does this automatically; SendGrid requires
using a different "to" field; Mandrill requires
`preserve_recipients=False`; Postmark doesn't
support *this type* of batch sending with merge data.)
* Allow message.from_email=None (must be set after
init) and message.subject=None to suppress those
fields in API calls (for ESPs that allow "From" and
"Subject" in their template definitions).
Mailgun:
* Emulate merge_global_data by copying to
recipient-variables for each recipient.
SendGrid:
* Add delimiters to merge field names via
esp_extra['merge_field_format'] or
ANYMAIL_SENDGRID_MERGE_FIELD_FORMAT setting.
Mandrill:
* Remove Djrill versions of these features;
update migration notes.
Closes#5.
