On 23-May-2002 at 01:11:56 Doughty, Michael wrote: > You are missing something. Email has a specific port associated > with various functions. For instance, SMTP is port 25. This port > is the one that the *server listens* on. Meaning if you want to > send some mail to that server (A), your server(B) chooses a random > port on it's side(X), and connects to A:25 saying to respond to B:X. > So the conversation has four parameters: Sending port and IP, > and receiving port and IP. It is the sending one that is randomized. > Yes, and it is the sending port that is blocked. That is my point. If a remote mail server sends a message to our mail server using a non-privileged port (i.e. the port they use to send the msg to us), and we block that port, then their mail server will simply see a dropped connection (or some such). If it happens to chose various ports that we have blocked, then it may well give up and tell the sender that it cannot send mail to our site.
John. ------------------------------------------------------------------------ John Horne, University of Plymouth, UK Tel: +44 (0)1752 233914 E-mail: [EMAIL PROTECTED] PGP key available from public key servers
