[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
* **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.
When using a stored template, SparkPost disallows
subject, text, and html. Django's EmailMessage default
empty strings are enough to provoke "Both content
object and template_id are specified" from SparkPost,
so remove them (if empty) when using stored templates.
Update docs and tests; add integration test for template_id.
Fixes#24
To conserve our ESP test accounts' send quotas, don't run
the live API integration tests 13 times in every Travis run.
Instead, just run them twice, on a representative set
of Python/Django combinations:
* Once on Python 2.7 (currently with Django 1.8)
* Once on Python 3.x (currently 3.5 with Django 1.9)
(Prep for running weekly tests on Travis cron.)
The *non*-integration tests still run on all combos.
* Introduce RUN_LIVE_TESTS environment var to control
whether live API integration test cases should run.
Default True, except in Travis-CI runs default False.
* Enable RUN_LIVE_TESTS in .travis.yml matrix for the
Python/Django combos listed above.
