import java.util.Hashtable;
import javax.naming.*;
import javax.naming.directory.*;

public class MXLookup {
public static void main( String args[] ) {
if( args.length == 0 ) {
System.err.println( "Usage: MXLookup host [...]" );
System.exit( 99 );
}
for( int i = 0; i < args.length; i++ ) {
try {
System.out.println( args[i] + " has " +
doLookup( args[i] ) + " mail  servers" );
}
catch( Exception e ) {
System.out.println(args[i] + " : " + e.getMessage());
}
}
}

static int doLookup( String hostName ) throws NamingException {
Hashtable env = new Hashtable();
env.put("java.naming.factory.initial",
"com.sun.jndi.dns.DnsContextFactory");
DirContext ictx = new InitialDirContext( env );
Attributes attrs = ictx.getAttributes( hostName, new String[]
{ "MX" });
Attribute attr = attrs.get( "MX" );
if( attr == null ) return( 0 );
return( attr.size() );
}
}