On which basis the suppression list is made?
There are four reasons behind the suppression list:
When the client is uploading the database on the portal, from that database if any email id is already in octane global suppression, then that email id will get filtered at the time of list upload.
If any email id gets a hard bounce, then that email id will be automatically added into the suppression.
If any email id gets more than 5 times soft bounce than in the next campaign, that email id will be treated as Hard Bounce and that email id will get automatically added into suppression.
If any client has already any suppression/blacklisted data then the client can directly upload under the suppression list to secure their domain and Ip reputation from SPAM/ABUSE and any other complaints.