Within an EmailAddress (previously ParsedEmail object), properties
now match Python 3.6 email.headerregistry.Address naming:
* .email --> .addr_spec
* .name --> .display_name
* .localpart --> .username
(Completes work started in 386668908423d1d4eade90cf7a21a546a1e96514;
this updates remaining uses of old names and removes them.)
[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.
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
python-sparkpost generates a transmissions.send
payload which is now considered invalid by the API,
if you try to use both `cc` (or `bcc`) and the
`recipients` dict structure required for merge_data.
[Anymail had been generating that recipients dict
structure in all cases, for simplicity. Sometime
between 2016-06-07 and 2016-06-22, SparkPost
began rejecting that if it appeared in the `header_to`
constructed by python-sparkpost.]
