The email address I am attempting to send to is one provided / hosted on 123-reg.
I received emails to that address if sent from my personal email, and I can also send emails back from within that inbox.
I have tested the contact form to make sure it works by first inputting my personal email address, and I receive the activation email as usual and once activated, can received contact sent via the contact form, directly to my personal email address.
However, when I use the email provided via 123reg, I don't receive the activation email at all. I've also checked spam folder, but nothing there either.
For anyone unfamiliar with formsubmit, here is the link: https://formsubmit.co/ -- what you see in the demo is pretty much all it takes to get a contact form set up. I've tried contacting them directly but it's been about a week or 2 and yet to receive a response.
If anyone can help, or suggest anything to help me figure out why it's not working it'd be much appreciated!