How to get default SMTP server name

Question

Hi,
I want to know the name default SMTP server configured in machine. How i can get this through my java code.
Help me on this

Answer 1

You can find STMP server configured in hostname, in ask to dns of domain who is mailserver, you need to find MX records :
- look a DNS config : NS (name server) , CNAME (Alias) , MX (mailexchange) etc...
import java.util.ArrayList;
import java.util.Hashtable;
import javax.naming.*;
import javax.naming.directory.*;
public class MXLookup
     public static void main(String args[]) throws NamingException
          System.out.println(getMX("altern.org") + " mail servers");
     private static ArrayList getMX(String hostName) throws NamingException
          // Perform a DNS lookup for MX records in the domain
          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 we don't have an MX record, try the machine itself
          if ((attr == null) || (attr.size() == 0))
               attrs = ictx.getAttributes(hostName, new String[] { "A" });
               attr = attrs.get("A");
               if (attr == null) throw new NamingException("No match for name '" + hostName + "'");
          ArrayList res = new ArrayList();
          NamingEnumeration en = attr.getAll();
          while (en.hasMore())
               String x = (String) en.next();
               String f[] = x.split(" ");
               if (f[1].endsWith(".")) f[1] = f[1].substring(0, (f[1].length() - 1));
               res.add(f[1]);
          return res;
}