Sending mail using javamail api from IBM Websphere Application Server

How to send mail using gmail from IBM Websphere Application Server 7 using javamail 1.4 api without using a certificate? I either get

javax.mail.MessagingException: Exception reading res开发者_如何转开发ponse; nested exception is: javax.net.ssl.SSLHandshakeException: com.ibm.jsse2.util.g: PKIX path building failed: java.security.cert.CertPathBuilderException: PKIXCertPathBuilderImpl could not build a valid CertPath.; internal cause is: java.security.cert.CertPathValidatorException: The certificate issued by OU=Equifax Secure Certificate Authority, O=Equifax, C=US is not trusted; internal cause is: java.security.cert.CertPathValidatorException: Certificate chaining error

or

Must issue a STARTTLS command first javamail

The same application works fine if I run it inside a main function in a java application. I have configured WAS mail sessions. Can someone please provide a working logic for the application and configuration in WAS for that?