Backups, either successful or not, don't send emails, but able to send emails via CLI. Error "could not render notification template"

[ajtatum]

So, I'm not sure if this is a Proxmox VE issue or a Proxmox Backup Server issue, so I apologize if this is the wrong forum.

After backing up, it shows "Backup job finished successfully" but then it shows:

INFO: target '<group-<mail-to-aj@mydomain.casa>>' is a group, notifying all members...
ERROR: could not notify via target `<mail-to-aj@mydomain.casa>`: could not render notification template: Error rendering "Unnamed template" line 3, col 1: could not render value "195421552640" with renderer HumanBytes

I don't know where it's getting groups from or what's going on.

However, on the PVE I have Postfix set up to relay through MailGun and when I do the command:

echo "Test mail from postfix" | mail -s "Test Postfix" aj@mydomain.casa

I receive the email.

I guess I'm not sure who's "responsible" for the notifications... if it's PVE or PBS.

Any help would be greatly appreciated!