We collected emailadresses on a stand last week. And we want to sent them one emailing, and afterwards delete the adresses.
Where can I add a preference if I upload all emailadresses form a csv document. So I dont mix this adresses with the existing ones.
When you import the emails you can set the preference (list) to associate them. Send the newsletter to that list and then, eventually, delete them. But pay attention: those are not separated list: if an address is already in your database, that address is updated with the list you set during import, so it would be better to not delete it.
Newsletter is not a tool for a single email, you should be easily send a single email with your email client and using the bcc field.