Currently we do not have notification emails per offload session.
There is a daily report email with the status of the offload. If the offload is successfully completed for all backups until the next report, there is no error notification in the daily report.
Does this happen to you often that the offload does give you a timeout?
Our next Veeam One release (V12) will offer more options for monitoring offload sessions.
Configure global notification settings to receive daily SOBR reports - it contains information about SOBR and its related activities. If the issue is permanent (it always happens instead of being sporadic), then you need to contact our support team for further investigation. Thanks!