Question Email form works with Gmail address but not with Webmail address. What?

[NyNyDanDan]

My Elementor form works just the way it's supposed to when a Gmail address is used but a WebMail address does not. I tried two different WebMail addresses - both WM addresses are GoDaddy based. I also tried it with a 1&1 address and it works fine. I cannot change the MX record in my GD Control Panel because that would mess up email functionality in other places. What do I need to do to get the GD WM to also work using the form? Thanks for your help!