Will manually uploaded contact to a list overrule unsubscription?

Hi there

I’m running a campaign on social media to collect e-mail-adresses for my company’s newsletter. I have set up flows in Klaviyo so I can just import a file of contacts to a list and a welcome e-mail will be sent. 

My plan was to upload a the same growing list of contacts every day, counting on Klaviyo to differentiate between new contacts on my list and contacts, that were added the first time a week ago (and therefore had already received a welcome email).

But now I have run into a problem: Some of the contacts (of course!) unsubscribe from the list after having received the welcome email. How do I make sure I do not resend e-mails to them when I keep on uploading the same, growing list?

The contacts agree to receive e-mail marketing from our company, so the file I upload has an email consent column. 

Hope you can help me out!