On 18-Jun-2003/06:38 +1000, Peter Kiem <[EMAIL PROTECTED]> wrote: >Michael, Michael, Michael, > >> Try telnetting to your mailserver on port 25, you can send the message >> directly, no server on your end involved. It's all plain Text. >> >> All an SMTP Server does is follow the protocol but any human being can do >> the same thing, it's all plain text. > >You miss my point. You are telnetting to a REMOTE server using the SMTP >protocol. >Anyone not running a local mailserver can do that. So what?
Anyone with a telnet client can do that. It does not matter whether they are running a local mail server (process listening on TCP port 25) or not. >If your dynamically assigned IP address is sending SMTP traffic directly to >remote hosts on the Internet (instead of only to your ISP) then either you >are: > >1) Running a local SMTP ***SERVER*** on/behind that IP address Incorrect. Pine, mutt, and probably some others, do not require a local SMTP listener (a server). They only require a program that can be invoked when needed to send outgoing mail. By default, they call sendmail as needed and by default, sendmail delivers directly to the destination SMTP server. This happens whether or not sendmail is already running a process that listens on TCP port 25. People that use this default config may run into problems if their visible IP address is not registered in the DNS or if the receiving ISP blocks SMTP connections from "residential" or dynamic IP addresses. These people do not need to be running an SMTP listener (a server) to have this problem. I think that the basic problem here is that you have not noted the difference between a process that runs continuously and listens for network connections (a server) and a process that may be invoked to connect to remote network resources (a client). Postfix runs separate processes for these functions, but sendmail does both in a single monolithic program. Sendmail's ability to perform both of these functions has apparently lead you into calling every invocation of SMTP a "server". Tony -- Anthony E. Greene <mailto:[EMAIL PROTECTED]> OpenPGP Key: 0x6C94239D/7B3D BD7D 7D91 1B44 BA26 C484 A42A 60DD 6C94 239D AOL/Yahoo Chat: TonyG05 HomePage: <http://www.pobox.com/~agreene/> Linux: the choice of a GNU Generation. <http://www.linux.org/> -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED] https://www.redhat.com/mailman/listinfo/redhat-list
