You should use apache-commons email validator. You can get the jar file from here.
Here is a simple example of how to use it:
import org.apache.commons.validator.routines.EmailValidator;
boolean isValidEmail = EmailValidator.getInstance().isValid(emailAddress);
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…