Proxmox is an Hypervisor with its Backup Server called PBS Proxmox Backup Server appliance.
Backup starts from the PVE node and the node send backup email log.
Important Note: if you have multiple nodes and vm's, of the same backup job, in different nodes, Proxmox PVE send an email from every node. This configuration is not supported from TrevorUtility. The only supported configuration is single node backup.
In MailMonitor we support this email log.
Proxmox PVE
Set Email Sender on Proxmox PVE: Datacenter - Notifications - mail-to-root - edit from address
Set Email Recipient on Proxmox PVE (this is the collector email or your email address forwarded to collector): Datacenter - Permissions - Users - E-Mail
Trevor MailMonitor
Device configuration
Job Configuration
Proxmox PVE
Datacenter - Backup - Edit Job - Note Template - Paste the subject you've found on Job Configuration