<subsystem xmlns="urn:jboss:domain:mail:1.0">
    <mail-session jndi-name="java:jboss/mail/gmail">
        <smtp-server ssl="true" outbound-socket-binding-ref="mail-gmail-smtp">
            <login name="<my gmail id>" password="<password>" />
        </smtp-server>
    </mail-session>
</subsystem>
...
<outbound-socket-binding name="mail-gmail-smtp">
    <remote-destination host="smtp.gmail.com" port="465"/>
</outbound-socket-binding>

@Controller
public class HomeController{
    @Resource(mappedName=java:jboss/mail/gmail)
    ...
}

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'java:jboss/mail/gmail' is defined: not found in JNDI environment