Email "Untrusted Signature"

I contacted my hosting company because emails sent from my domain have my name in red with the message "Untrusted Signature. Mail was unable to verify the authenticiy of the S/MIME certificate.

So far, my hosting company cannot help me and have escalated me to support level 2.

This is my current trust store…

Trust store version: 2022012800

Trust asset version: 17

I need help resolving this issue. This is my work email and I need to be considered trustworthy by my recipients!