Work-around SendGrid 403

Author: c-w

opwen_email_server/services/sendgrid.py

@@ -100,7 +100,23 @@ def _create_email(self, email: dict, email_id: str) -> Mail:
         mail.add_content(Content('text/html', email.get('body', '(no content)')))
         self.log_debug('added content to email %s', email_id)
 
-        mail.from_email = Email(email.get('from'))
+        # at some point SendGrid had the ability to send from subdomains of a verified
+        # domain, so verifying {domain} let us send from {client}.{domain}
+        # ...this feature went away so the following is a work-around which
+        # changes the from address to the verified root domain but using reply-to
+        # so that the email still gets routed back to the original client
+        # ...this is a pretty ugly hack and the real fix is to change the logic of
+        # how we sign up users on clients to use the new format {user}-{client}@{domain}
+        from_email = email['from']
+        user, client_domain = from_email.split('@')
+        client_domain_parts = client_domain.split('.')
+        if len(client_domain_parts) == 3:
+            client = client_domain_parts[0]
+            domain = '.'.join(client_domain_parts[1:])
+            mail.from_email = Email('{}-{}@{}'.format(user, client, domain))
+            mail.reply_to = Email(from_email)
+        else:
+            mail.from_email = Email(from_email)
         self.log_debug('added from to email %s', email_id)
 
         for i, attachment in enumerate(email.get('attachments', [])):