Hi Lee,
Welcome back! Thanks for reaching out, though I’m sorry to hear that you are having an issue with your emails.
As a first troubleshooting step, could you please provide us with your complete system information in a private reply using the instructions found in the following link?
https://theeventscalendar.com/knowledgebase/sharing-sys-info/
Alternatively, you can just bypass the WordPress servers 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 it goes! Have a great weekend!
Thanks,
Jaime