Am Montag, 21. Juli 2003 22:18 schrieb JoeHill: > Hello, > > I am on a small internal LAN which does not use a Domain name or even > have a DNS server, well, except for the router in a way I suppose. > > Anyway, I want to try to use my mailserver, simply called "localhost", > to send mail out rather than my ISP's smtp server. Mainly a learning > exercise, you know, start small and all that. > > I have used sendmail in the past and run into several problems wherein > receiving domains see me as an "open relay" and bounce the mail back to > me as potential spam.
They don't do it weil because they see you as an open relay but because you have a dynamic IP address and those addresses were missused for spaming. They take the easy way and block whole known dynamic IP address ranges (It is something like that: oh, there are drivers of rented cars who can not drive so to be sure none of those drivers get on our roads lets block our roads to all rented cars). > > I a looking at the postfix docs right now, and I am confused about a few > things. > > In my mail client, I choose sendmail for sending mail, but how does this > relate to Postfix? Does Postfix simply receive all commands from > sendmail and process them? postfix has a sanemail compatibility layer. the postfix/sendmail has nothing to do with the sendmail program. It is only called the same. There are some programs out there which needs a programm called sendmail with the known functionality of the famous sendmail. > > If so, how to I configure Postfix (I am assuming this is in > /etc/postfix/main.cf) to let receivers know I am not an open relay and > they have nothing to fear from me. You can not. All the big ISP which reject your mails don't care wether you can send mails from your own mailserver or not. > I read in the docs that by default > Postfix will not relay mail by default, so I rest easy that I am *not* > an open relay, correct? It is not that easy. To run a mailserver is mor than to install postfix. you are responsible for your configuration and your users who are allowed to use your mailserver. And there are so many poor installed and configured mailserver out there. It is hard to collect all this servers with static ip addresses, but with dynamic addresses it is not possible. And, your intention may be not to build a open relay, but are you shure you ar the only person, who is able to configure your server? So, you may know that your server is save, but the rest of the wold only may guess. And you are not able to give a guarantee. Your server can not get prooven while changing the IP address. > > Anyhow, thanks for any assistance! So, in the beginnig, configure your mailserver to use the mailserver of your ISP as a relay. Please see the postfix FAQ on www.postfix.org. There are some config examples for this special needs. Martin -- ------------------------------------------------------------ H E L I X Gesellschaft f�r Software & Engineering mbH ------------------------------------------------------------ Hanauer Landstrasse 52 Telefon (069) 4789 35-30 D-60314 Frankfurt am Main Telefax (069) 4789 35-44 ------------------------------------------------------------ http://www.helix-gmbh.net [EMAIL PROTECTED] ------------------------------------------------------------
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