This error has happened in 2 separate email accounts, through separate email servers.   So I suspect that it is a Zoho email error (via CRM).   Please advise.  

Reason:java.security.NoSuchAlgorithmException: Error constructing implementation (algorithm: Default, provider: SunJSSE, class: com.sun.net.ssl.internal.ssl.DefaultSSLConte

Another error.   Please advise. 

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

I can see new emails via my webmail access to my server but they are not being transferred to my Zoho client.  Please advise.