• Keeps per-host status info. It needs to be shared among all Internet Routers.

• Operation: update(domain,ip) Update SMTPCache records for host and/or domain. Call

    MAIL FROM:
        mit = Director.createMit();
        mit.state = STATE_INCIPIENT;
        try {
            Director.headPipe.route(mit, true, null);
        } catch (Exception e) {
            Send error status to client.
            mit = null;
            return;
        }
    for each (RCPT TO:) {
        try {
            Director.headPipe.route(mit, true, null);
        } catch (Exception e) {
            Tell client that this recipient not allowed.
        }
    }
    DATA: (? skip this ?)
        try {
            Director.headPipe.route(mit, true, null);
        } catch (Exception e) {
            Send error status to client.
            mit = null;
            return;
        }
    mit.state = Mit.STATE_ROUTENOW
    mit.persist(false);
    // MIT will send it as soon as it can.  Don't want to make the
    // client wait for us after we have persisted it.

• BULK TRANSMITS done by 1-level recursion, not by multithreading. (I think no need to check for recurse since there is no way to recurse other than 1 level in our recursion one case.

• This incurs no multi-threading, although we have to deal with the existing multithreading in SMTPSession).

• Always SMTPCaching.update(domain,ip) after every successful or failed conn.

• Don't use the Incoming server for outgoing unless client ran ETRN.

• It would be nice to use JavaMail, but I don't know if that supports bulk xmits. If not, could still use JavaMail for prototyping the SMTPSharedConsumer.

• After first successful xmit to this domain, run

      Director.routingRun("nextPipe == " + mypipe
       + "destdomain == '" + destdomain + "'");
      If there are more Mits for this target ipaddr, then this
           router() method will be called recursively.
       ++recursecount;
       try {
          if (recursecount > 1) {
              if (state != STATE.GREETED) throw... // assertion
              piggyback(mit);
              return;
          }
      } finally { --recursecount; }
      piggyback(mit) {
          out.println(mit.this...
          flush();
          return;
      }

• • Always SMTPCaching.update(domain,ip) after every successful or failed conn.

  • Need to maintain a ETRN mode HashMap of currentThread X session.

  • When a SMTPSession gets an ETRN, it can run

            Director.routingRun("nextPipe == " + myPipe
             + ip == '" + ipaddr + "'");
        SMTPServer.route(Mit mit, boolean ping) {
            if (ping == true) return;
            session = (SMTPSession) etrnSessions.get(Thread.currentThread());
            session.piggyback(mit);  // Same as in SMTPSession
            return;
        }