utils: add setting to choose email sending format (#50745)

src/authentic2/app_settings.py

@@ -354,6 +354,9 @@ default_settings = dict(
     A2_DUPLICATES_BIRTHDATE_BONUS=Setting(
         default=0.3,
         definition='Bonus in case of birthdate match (no bonus is 0, max is 1).'),
+    A2_EMAIL_FORMAT=Setting(
+        default='multipart/alternative',
+        definition='Send email as "multiplart/alternative" or limit to "text/plain" or "text/html".'),
 )
 
 app_settings = AppSettings(default_settings)

src/authentic2/utils/__init__.py

@@ -30,6 +30,7 @@ from importlib import import_module
 
 import django.apps
 from django.conf import settings
+from django.core.mail import EmailMessage
 from django.http import HttpResponseRedirect, HttpResponse
 from django.core.exceptions import ImproperlyConfigured
 from django.http.request import QueryDict
@@ -666,14 +667,26 @@ def send_templated_mail(user_or_email, template_names, context=None, with_html=T
     html_body = None
     html_body_template_names = [template_name + '_body.html' for template_name in template_names]
     html_body_template_names += legacy_html_body_templates or []
-    if with_html:
+    if with_html and app_settings.A2_EMAIL_FORMAT != 'text/plain':
         try:
             html_body = render_to_string(html_body_template_names, ctx, request=request)
         except TemplateDoesNotExist:
             html_body = None
 
-    send_mail(subject, body, from_email or settings.DEFAULT_FROM_EMAIL, [user_or_email],
-              html_message=html_body, **kwargs)
+    if app_settings.A2_EMAIL_FORMAT == 'text/html':
+        msg = EmailMessage(
+            subject, html_body, from_email or settings.DEFAULT_FROM_EMAIL, [user_or_email], **kwargs
+        )
+        msg.content_subtype = 'html'
+        msg.send()
+    elif app_settings.A2_EMAIL_FORMAT == 'text/plain':
+        msg = EmailMessage(
+            subject, body, from_email or settings.DEFAULT_FROM_EMAIL, [user_or_email], **kwargs
+        )
+        msg.send()
+    else:
+        send_mail(subject, body, from_email or settings.DEFAULT_FROM_EMAIL, [user_or_email],
+                  html_message=html_body, **kwargs)
 
 
 def get_fk_model(model, fieldname):

tests/test_utils.py

@@ -177,6 +177,26 @@ def test_send_templated_mail_template_vars(settings, simple_user):
     assert sent_mail.body == 'here is the text body\n'
     assert sent_mail.alternatives == [('here is the html body\n', 'text/html')]
 
+    settings.A2_EMAIL_FORMAT = 'text/plain'
+    send_templated_mail(simple_user, ['template_vars'])
+
+    assert len(mail.outbox) == 1
+    sent_mail = mail.outbox.pop()
+    assert sent_mail.subject == 'here is the subject'
+    assert sent_mail.body == 'here is the text body\n'
+    assert sent_mail.content_subtype == 'plain'
+    assert not hasattr(sent_mail, 'alternatives')
+
+    settings.A2_EMAIL_FORMAT = 'text/html'
+    send_templated_mail(simple_user, ['template_vars'])
+
+    assert len(mail.outbox) == 1
+    sent_mail = mail.outbox.pop()
+    assert sent_mail.subject == 'here is the subject'
+    assert sent_mail.body == 'here is the html body\n'
+    assert sent_mail.content_subtype == 'html'
+    assert not hasattr(sent_mail, 'alternatives')
+
 
 def test_lazy_join():
     a = 'a'