They are being sent, they’re just not being received. The default WP php Mailer is not really meant for long term use, because mails sent using that are often flagged as spam by the likes of Gmail and Yahoo, due to lack of proper authentication. The best course of action is to use an SMTP plugin like WP Mail SMTP by WP Forms. All emails sent from my sites using this method are being sent and received fine.
What’s in /var/log/maillog?
There are many factors that affect email deliverability and it will be hard to guess which is the cause without you sharing your mail error log.
In the meantime, you may try to manually setup PHPMailer or use an SMTP Plugin as instructed by Sean.
If I have MX records from Google and a domain from Godaddy could I configure my mailer to .org company email address? Or am I stuck with the top ones and cannot customize?
If mail is intermittent, use one of the many SMTP plugins.
How do I configure my WP Mail SMTP Lite to work with my own domain? To use [email protected]?
I recommend asking at https://ww.wp.xz.cn/support/plugin/wp-mail-smtp/#new-post so the plugin’s developers and support community can help you with this.