Cannot send emails - Sun Security error message

Cannot send emails - Sun Security error message

Hi,

We are not able to respond to any emails via Zoho.

The following error message is received when trying to respond to or send an email:

  1. error: sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target 

Can you help please?

Paul