How to see pending mail notifications

Hi, apologies if this is the wrong category but I had no idea where to post this, since the problem at hand might be solved either by a fully-fledged feature request or a simple addition in the documentation.

I am 99% sure that this is due to me not setting up a proper SMTP server in nextcloud’s basic configuration, so I’m not particularly worrying about it, but my logs are full of these kinds of entries :

{"reqId":"DuExNXuKZmI8gtIiIqwx","level":3,"time":"2022-09-20T07:35:02+00:00","remoteAddr":"","user":"--","app":"notifications","method":"","url":"--","message":"Connection could not be established with host :stream_socket_client(): Unable to connect to ssl:// (Connection refused)"}

Curiously, sometimes the user field contains my admin user, sometimes it’s blank (but it’s always the same exception).

I have several questions about this :

  • How can I see the contents of these mysterious mails that are not sent ? Are they queued/stored/logged somewhere ? (I’m assuming yes, given that the aforementioned log entries repeatedly appear precisely every 5mns, which is exactly the CRON interval I have configured for NC’s background jobs).
  • Are they strictly equivalent to the push notifications (assuming both checkboxes are ticked in the activity settings) or do they contain more detailed information ?
  • Again referring to these checkboxes in the activity settings, does the category “Security” include app updates availabilities ? (I am having quite a lot of these entries despite having mostly only Security alerts ticked under the e-mail column, so i’m wondering if I’m missing a lot of important notifications)

Thank you for your time