WordPress emails stop sending when site URL or WP URL are changed

I’ve discovered an issue on my wordpress site – no emails are being sent – for new user creation, when comments are written, or when a contact form (contact form 7 or jetpack) are filled out. The emails are not sent to spam or regular inbox.

I even installed WP fresh and was able to get emails to send, but when I set the WP URL and Site URL to make the website live, emails stop working.

So my WordPress site is installed at http://www.stephenemlund.com/icphotobooth2 – but the live domain name (and what I’ve changed WP URL and Site URL to is http://www.iowacityphotobooth.com

I’ve tried installing and activating WP-Mail SMTP using various settings – both GMail and Godaddy settings and this didn’t solve the issue

I’m using Godaddy Shared Hosting on Linux, btw.

What could cause WordPress emails to stop sending when a the WP URL and/or Site URL is changed?