SSLHandshakeException while trying to send mail from java Program.

I am using Java to send mail through Zoho mail

props.setProperty("mail.smtp.host", smtp.zoho.com);

props.setProperty("mail.smtp.socketFactory.class", "javax.net.ssl.SSLSocketFactory");

props.setProperty("mail.smtp.socketFactory.fallback", "false");

props.setProperty("mail.smtp.port", 465);

props.setProperty("mail.smtp.socketFactory.port", 465);

props.put("mail.smtp.starttls.enable", "true");

props.put("mail.smtp.auth", trueOrFalse);

props.put("mail.transport.protocol", "smtp");

Getting this error:

javax.mail.MessagingException: Could not connect to SMTP host: smtp.zoho.com, port: 465;

nested exception is:

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

Can you please correct me where it is going wrong.