Can I bring my contacts from another email platform?
Yes. Export them as a CSV from your old platform and upload it to a list. Keep its status column, and anyone it marks unsubscribed, bounced or invalid stays off that list.
Yes. Every email platform can export your contacts as a CSV file, and that's all you need.
Bring them across
In your old platform, export your contacts as a CSV, with the status column.
Here, make a list and upload the file: Upload and clean your list.
On the mapping step, set the status column to Status (unsubscribed, invalid, blacklisted…).
Unsubscribes come too
Anyone the status column marks as not to be mailed, like unsubscribed, bounced, invalid or blacklisted, is unsubscribed on that list. A status can take someone off, and never puts anyone back on.
Every address is checked again on the way in, whatever your old platform said about it.
Taking someone off by hand: Handle unsubscribes.