Better to open a support ticket regarding that, but most likely there's a problem with connecting to our Amazon SMTP servers, so before creating a ticket I suggest to make sure that AWS servers can be reached from your machine and no-replyatcloudberrylabdotcom is white-listed in your mail filter.
They do not get any more informative if I increase the log level to debug :(
What are the servers and ports it is trying to connect to? If I try to look them up (dig cloudberrylab.com MX) I get Google mail servers.
The CBB instance right now is in an Amazon Lightsail container, it took a bit of work to get that thing to send mail at all , but it does send mail externally.
CBB was sending notifications initially
I had to change the plans to root.root ownership to get it to backup some files/folders
that's when it (mail notifications) stopped working
changing ownership back or trying to create a new plan still show the "cannot reach" error.