Contacts have been 'unsubscribed by me' even though I didn't unsubscribe them

[JoCoPIO]

I send an email newsletter to our 4000+ employees each week (and now daily, due to the coronavirus outbreak) and I am hearing from many of our employees that they are not receiving the email. When I go to look them up in the contact database, it says they were 'unsubscribed by you' at some point in the past - the date varies broadly. I am not unsubscribing employees from our database so I don't know how this is happening. 

My only guess is that it might have to do with the way our list is managed - every week, we run a report of every active employee and upload their email address as a new list, then we delete the old list from the previous week. This way, we only send to active employees - new employees added, former employees removed. This doesn't seem like the ideal way to handle our list (the process was in place before I started here) and I'm wondering if this is the culprit for our mystery unsubscribes. Is there a better way to be handling this list? Or is something else causing my problem? It's getting to be a real pain to have to add employees back to the list all the time.

Thanks! 

[Frankie_P]

Hi @JoCoPIO 

Thank you for reaching out about your contacts! Though our Chat Support was able to further assist, I wanted to make sure we shared our response here in the Community as well. The contact examples you provided this team did display to have been unsubscribed through your account as described. They suggested your contacts may have been accidentally unsubscribed by another user on your account through our bulk upload of unsubscribed contacts feature.