How to save unchecked dynamic checkbox array?

I have this html code that has as many copies as the user would like though a button that adds another set

<input type="email" class="regular-text" id="customer_email_address[]" name="customer_email_address[]" placeholder="Email Address" />
<input type="text" class="regular-text" id="customer_email_password[]" name="customer_email_password[]" placeholder="Password" />
<input type="checkbox" id="customer_email_create[]" name="customer_email_create[]" />

My issue is that while I can save checkboxes that are checked with PHP, I can't determine which ones are unchecked.

How would I go about doing something like this?