InboundEmailHandler in Salesforce

Salesforce

How to populate SourceId in Case in InboundEmailHandler Email Service in Salesforce?

Sample Code: global class createCaseInbound implements Messaging.InboundEmailHandler { global Messaging.InboundEmailResult handleInboundEmail(Messaging.InboundEmail email, Messaging.InboundEnvelope env) { Messaging.InboundEmailResult result = new Messaging.InboundEmailResult(); String myPlainText= ''; myPlainText = email.plainTextBody; try { Case objCase ....