Fixed #12666 -- Added EMAIL_USE_LOCALTIME setting.

When EMAIL_USE_LOCALTIME=True, send emails with a Date header
in the local time zone.

django/conf/global_settings.py

@@ -194,6 +194,9 @@ EMAIL_HOST = 'localhost'
 # Port for sending email.
 EMAIL_PORT = 25
 
+# Whether to send SMTP 'Date' header in the local time zone or in UTC.
+EMAIL_USE_LOCALTIME = False
+
 # Optional SMTP authentication information for EMAIL_HOST.
 EMAIL_HOST_USER = ''
 EMAIL_HOST_PASSWORD = ''

django/core/mail/message.py

@@ -316,7 +316,11 @@ class EmailMessage(object):
         # accommodate that when doing comparisons.
         header_names = [key.lower() for key in self.extra_headers]
         if 'date' not in header_names:
-            msg['Date'] = formatdate()
+            # formatdate() uses stdlib methods to format the date, which use
+            # the stdlib/OS concept of a timezone, however, Django sets the
+            # TZ environment variable based on the TIME_ZONE setting which
+            # will get picked up by formatdate().
+            msg['Date'] = formatdate(localtime=settings.EMAIL_USE_LOCALTIME)
         if 'message-id' not in header_names:
             # Use cached DNS_NAME for performance
             msg['Message-ID'] = make_msgid(domain=DNS_NAME)