Joon Guillen wrote: > Hi, > > Does the SMTP service use the same port (25) to connect and forward the > outgoing e-mails to its designated mail servers or do they use the ports > above 1023? And, will the remote mail server need to respond to it (as an > acknowledgement, or maybe something else)?
Yes, SMTP uses ports 1024 and above to send out mails, and the remote mail servers do need to respond to sending client. > I'm doing firewall rules, and I'd like the rules to be as specific as > possible. I'm using qmail and qmail-smtpd btw. Here are the rules: # SMTP client (25) # ---------------- ipchains -A input -i $INTERNAL_INTERFACE -p tcp ! -y \ -s $SMTP_SERVER 25 \ -d $INTERNAL_IPADDR $UNPRIVPORTS -j ACCEPT ipchains -A output -i $INTERNAL_INTERFACE -p tcp \ -s $INTERNAL_IPADDR $UNPRIVPORTS \ -d $SMTP_SERVER 25 -j ACCEPT Note: $UNPRIVPORTS="1024:65535" -- Benjamin Oris Jr. ImagineAsia Digital Animation Studio http://www.imagineasia.com _ Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph To leave: send "unsubscribe" in the body to [EMAIL PROTECTED] To subscribe to the Linux Newbies' List: send "subscribe" in the body to [EMAIL PROTECTED]
