EMAIL ERROR: Invalid address: (From): root@localhost" while reading response header

I am getting this error in the web log. It occurs when a patient is attempting to send/update information. I am attempting to use SMTP, not PHPMail. I am not sure why this is happening.
My server is a FreeBSD 12.1-RELEASE with OpenEMR-5.0.2_3, PHP-7.4 and Nginx-1.18
Any ideas?

I forgot to mention that my patients are unable to enter information in the portal. They are getting this error: “something went wrong”.

Thanks