Not working for Internet Exploer/ Edge

Afternoon, I am having issue with the plugin, issues that I didn’t have before, where the pop shows up and the user fills info to they would receive and email to get a coupon. Now everything works fine on all browsers up to the point of submit. Where on Chrome and Firefox the users receives the email within minutes of submission however on IE 11 and Edge when filling out the form and hitting submit, resolves the same way visually on IE and Edge however the email never comes. No sure why it broke now, maybe plugin updated and is acting funky but please any help or advice would be great.