contact form only submits first time

ok, after testing here is a problem I need to solve:

my contact form will only send the message if the email isn’t already in the database.

I use a unique email the first time and the message sends perfectly, but if I where to return to that form later and submit another message, it wouldn’t go through. (and it isn’t getting spammed)

It works great for a subscription form, but not great for a contact form, as the same person may be contacting me several times the same way.

https://no2contracting.com/contact-us/

thanks in advance. any help would be excellent!

https://www.ads-software.com/plugins/contact-form-7/