Email Marketing - Multiple emails at once

My current company does email marketing for clients. My job scope for some of the clients includes, designing the look and feel, creation of the edm in HTML, and blasting the edm.

There are many important things we look out for when creating and sending out to clients' databases. For example. In creation, we have to ensure that the edm show up properly in different desktop and web email clients, no misalignment. And in blasting, we have to ensure no duplicate email and not sending to recipients who have already unsubscribed.

I just checked my email inbox. And I was surprised. I had received the same email, EIGHT times. Hmm.. Did their email marketing system not check for duplicates? Not that I remember I subscribed for this deal site either.

One of the danger of such incidents can cause recipients to simply mark the email as spam, thus, endangering the reputation of the sender's email.

And me? I trashed it even before reading.. How would I even feel like reading when the moment I open the email, what I saw is... that...