@@ doesn't work in mail template

[aleung]

In mail template, #{a @Application.index()}Home#{/a} works, but #{a @@Application.index()}Home#{/a} get error:

play.exceptions.TemplateExecutionException: No such field: Application for class: play.templates.Template$ExecutableTemplate$ActionBridge
        at play.templates.Template.throwException(Template.java:266)
        at play.templates.Template.render(Template.java:231)
        at play.mvc.Mailer.send(Mailer.java:189)
        at notifiers.Mails.commentReplied(Mails.java:12)
        at controllers.Blog.replyToComment(Blog.java:287)
        at play.utils.Java.invokeStatic(Java.java:129)
        at play.mvc.ActionInvoker.invoke(ActionInvoker.java:138)
        at Invocation.HTTP Request(Play!)
Caused by: groovy.lang.MissingFieldException: No such field: Application for class: play.templates.Template$ExecutableTemplate$ActionBridge
        at /app/views/Mails/commentReplied.html.(line:3)
        at play.templates.Template.render(Template.java:208)
        ... 6 more