Can you also show how you send this in your form/view?
My guess is that you are either sending as request parameter or get method as parameter in method.
This is not the preferred way of doing it.
You're using String concatenation to create the query string. It can work, but it is realy eror-prone such as in your case. You're missing the single quotes around the email address that's the reason that it doesn't work.
Try the following:
String myquery = "select u from AuthenticationInformation u where u.email=' " + emailadd + " ' ";
The best way to prevent these kind of error is to use parameters in you query as you already tried. Something like:
String myquery = "select u from AuthenticationInformation u where u.email = :email"; q.setParameter("email", emailadd);
The name of the parameter is WITHOUT the