EmailMultiAlternatives.send() raises error when `to` isn't a list

[djoume@…]

Hi,

Following ​http://www.djangoproject.com/documentation/email/, I have tried the example :

from django.core.mail import EmailMultiAlternatives

subject, from_email, to = 'hello', 'from@example.com', 'to@example.com'
text_content = 'This is an important message.'
html_content = '<p>This is an <strong>important</strong> message.'
msg = EmailMultiAlternatives(subject, text_content, from_email, to)
msg.attach_alternative(html_content, "text/html")
msg.send()

This raise a "cannot concatenate 'str' and 'list' objects" error.
The exception is raised by return self.to + self.bcc (line 251 in mail.py)
because bcc is set to [] by default (line 209 of mail.py) and in this example to is a string.

To fix this I had to use ['to@example.com'] instead of 'to@example.com'

Another solution is to changed __init__() to force self.to and self.bcc to being list.

[Chris Beaven]

Plain case of user error - to should always be a list (as the documentation clearly shows). Coercing to to a list wouldn't achieve much, you'd just end up with ['t', 'o', '@', ...]