This is my operation contract. I want to test this method in a browser. But when I type any email in the browser like http://localhost:1234/json/user/abc/abc@abc.com
http://localhost:1234/json/user/abc/abc@abc.com
Try to URL encode your e-mail address:
http://localhost:1234/json/user/abc/abc%40abc.com
Does that result in the call you expect?