Log when not all emails could be sent

src/argus/notificationprofile/media/email.py

@@ -41,7 +41,7 @@ def modelinstance_to_dict(obj):
     return dict_
 
 
-def send_email_safely(function, additional_error=None, *args, **kwargs):
+def send_email_safely(function, additional_error=None, *args, **kwargs) -> int:
     try:
         result = function(*args, **kwargs)
         return result
@@ -183,17 +183,25 @@ def send(cls, event: Event, destinations: Iterable[DestinationConfig], **_) -> b
         email_addresses = cls.get_relevant_addresses(destinations=destinations)
         if not email_addresses:
             return False
+        num_emails = len(email_addresses)
 
         subject, message, html_message = cls.create_message_context(event=event)
 
+        failed = set()
         for email_address in email_addresses:
-            send_email_safely(
+            sent = send_email_safely(
                 send_mail,
                 subject=subject,
                 message=message,
                 from_email=None,
                 recipient_list=[email_address],
                 html_message=html_message,
             )
+            if not sent:  # 0 for failure otherwise 1
+                failed.add(email_address)
 
+        if failed:
+            LOG.warn("Email: Failed to send to %i addresses", len(failed))
+            LOG.debug("Email: Failed to send to:", " ".join(failed))
+            return False
         return True