fix(send_mail): Save after each sent mail, as the bottleneck is in the SMTP

elections/utils.py

@@ -461,9 +461,8 @@ def send_mail(election: "Election", subject: str, body: str, reply_to: str) -> N
     for m, v in messages:
         try:
             m.send()
+            v.has_valid_email = True
         except smtplib.SMTPException:
             v.has_valid_email = False
-        else:
-            v.has_valid_email = True
 
-    User.objects.bulk_update(voters, ["password", "has_valid_email"])
+        v.save()