UNIX for Dummies Questions & Answers

suse linux 6.4 im running and i have port 110 for pop and smtp open, i have set up some email addresses for my friends, but they recieve errors saying that relaying is denied. i know this is to prevent spamming software from using my domain to send spam, but how do i let my users send their mail? it works for people at my domain, but when they try to send mail to others, eg; @aol.com
mail relaying is denied. now to fix this i could add their ip addresses to the list of "$mynetworks" but what if they are using dynamic ip addresses? im using postfix, further more, one user who is connected with verison dsl is being disconnected from her isp whenever an attempt is made to check mail at my server. shouldnt they be able to send mail to whomever they want after they supply their user name and password? thanks for anyhelp.

What MTA are you using to relay mail, sendmail?

If you are using sendmail, you can define a domains and hosts that are allowed to use (relay) the mail server.

Check this link for more details:

http://www.sendmail.org/tips/relaying.html

im using postfix. most users are dial up with dynamic ip's, is there a way to allow relaying only to users who supply their user name and password? ive looked through documentation, and a few postfix websites, (postfix.com) and cant find this solution. what confuses me is this, how do other companies give out pop3 email addresses allow their users to send mail to outside networks? say, i connect from computerA@dynamic-ip.aol.com to myserver@myserver.com, to send an email whose address is userB@emailaccount.com?

Sorry, I use sendmail and can't speak to postfix..... perhaps someone else can help you who uses postfix.

Do a Google Search on "POP before SMTP" and "PostFix". This configuration denies external users the abilty to use SMTP until after they have been verified by POP3. It's a nifty way around the problem of those dynamic IP addresses.

Oh yeah. That reminds me. You'd be surprised how loose ISPs are with their SMTP relaying by IP address. My DSL provider is [censored] and I can send e-mail through the [censored] relay which is normal. Because the [censored] SMTP relay only goes by IP address and no other verification, I can relay mail as my Father (who is also a [censored] customer) using his e-mail address just because our IP addresses are allowed into the SMTP relay. No passwords are required.

I did that one day to demonstrate how loose the [censored] e-mail server was and how easy it is for spammers to pretend to be somebody else.

A lot of corporations are lax that way as well. As a joke we once sent a co-worker a "Your Fired!" from the CEO of [censored]. It was quite amusing.... for the rest of us!

hahaaha i can imagine! but yes it is suprising , im sure lots of people recieve spam that they think is from their ISP. anyway, thank you very much for the info, ill post back with the solution and if it works. thanks again auswipe and neo!