I recently entered our database into a subscriber list (imported from FileMaker), and then was told many of them were to be taken out. So I thought the easiest way to do it was to update the FileMaker database, delete all the email addresses in the CM account and import the modified file.
Except when I did this, all the emails I had previously deleted would not go in, as they were in some sort of blacklist.
I found that there seems to be no obvious way to wipe all the emails from the list and start again, apart from starting a new list (and setting up segments, custom fields etc all over again) is there an easier way?
I think you're talking about the client suppression list. You can view and modify it by clicking "Manage Subscribers", and clicking "Client-wide suppression list for [...]" at the bottom of the page.
From there, you can click "Select" in the title row, and "Remove selected" at the bottom of the page. Repeat until your list is empty, and you're back to square one.
However, if your lists has a great number of subscribers, I'd recommend you just delete the client and create it all over. Click "Manage Clients", "Delete this client", and "Add New Client".
Is this the only way to delete lot of subscribers out of your suppression list?