Thanks so much for reaching out!
I’m sorry that you are experiencing this issue!
You can try bypassing the WordPress email system altogether and have the system send tickets from any chosen email address by simply installing, configuring and testing the following plugin: https://wordpress.org/plugins/easy-wp-smtp/
Using a real SMTP server with authentication will bypass the built-in WP mail functionality altogether.
Please make sure you configure and test the settings using the plugin’s built-in tool.
Let me know how that goes and if you have any other questions on this topic!
Thanks,
Jaime