Get the Client for a given email address. 

This returns the basic client details (Surname, Given Name and Code) which match the given email address. Will return the client regardless of whether the client has been web published. If there is no match for the given email address, or more than one client has that email address, an error will be returned in the TAuthenticate. 

This could be used as an alternative way to find a client if, for example, they can't remember their account details. 

The Client is represented by a TClie. 

A token is passed for authentication. If the authentication fails, or other errors occur, no client is returned. The result of the authentication is represented by a TAuthenticate object. 

This function has security level "Protected", and can only be accessed by users that have explicitly been granted permission to the API.

[WebMethod(Description = "Gets the client with the specified email address")]
public TAuthClie GetClientByEmail(string token, string emailAddress);