Postfix help please!

[rick420]

I recently purchased a domain name and have it all set to point to my box and all that. (high-on-linux.net)I wanted the domain name to use my box as a mailserver for me and a few friends mostly.

Anwyays, I got Postfix working...somewhat. My personal user name has no problem receiving email or sending it. Anyone else has usually been able to receive (sometimes it errors out) but never have been able to send out thru me (using username@high-on-linux.net) They get an error about relay access being denied when trying to send. Sometimes the receiving part works, and sometimes it gives a "unexpected connection problem" (most of the other accounts are users using windows).

I connect to the net thru a router, and have port 25, and 110 forwarded to my box. I assume its an option in Postfix that is the problem, I just dont know where to start looking. Im totally new to this mailserver stuff as well. Any help would be great.

[scanez]

So are the others using computers NOT on your network when trying to send? If so, that is probably the problem. Postfix by default only allows computers in the same network as the server to send email. Try adjusting the "mynetworks" and "mydomains" options in the Postfix config if this is the problem (I think those are the two options to look at, mydomains may be wrong...check into it )

SC

[rick420]

Thanks for the quick reply.

I saw that in there somewhere but I was confused. I mean I would have to manually add anyones IP that I wanted to let sendmail? For example say you wanted an account, I would have to put your IP in there to let you use it to send?

If I want to let anyone that has an account send thru me, what would I need to add? Thanks again

[chikn]

The best way is to set the clients up to use the SMTP server of their ISP and your mail server as POP because if you open it up to relay you will be taken advantage of speaking from personal experience. Or you can setup webmail to which they could send and receive through.

[rick420]

What do you mean by being taken adavtage of? What are my worries in letting people send their mail thru me?

I thought of webmail, but figured it would be hard to set up since I dont know much about making webpages. I really just wanna figure out how to let people send thru me, and why some people seem to be blocked from even receiving mail. Is there anything special I should do when I create their username? I just use adduser and passwd for it right now. Thanks again

[Radar]

What do you mean by being taken adavtage of?

Becoming a spam relay.

[rick420]

But there has to be a way to stop that as well right? And Im not gonna have more than 10-20 users if that using my email server.

Basically I wanted to start getting more into the server parts of Linux and started with purchasing domain and getting email server up and working. Eventually i will have another box as my desktop and wanted to use my current box as a standalone mail server, DNS server, and FTP probably. Maybe a little www as well.

Basically I just want to get it sending mail, then I will worry about securing it. thanks again

[chikn]

Think of it this way. Your ISP will only let you send mail if you dial up to it or are on the same network but it will let you check mail from anywhere using its POP server. This is common practice because if you allow relaying then anybody can send massive amounts af spam through your system making you look like the bad guy. And trust me if you leave it open somebody will find it.

Different relay domains can be setup but with 20 people using it from different locations that wouldnt be that difficult. Although Ive never really tried it as it doesnt make sense to want to send through my SMTP server when I can use my mobile peoples ISPs SMTP server.

Use this method if you want use the network names to allow relaying

#mynetworks = $config_directory/mynetworks
#mynetworks = 168.100.189.0/28 127.0.0.0/8

Create the mynetworks file and include all domain names that might be realying mail or use the other option and input the IP ranges of each user.

[rick420]

Thanks for explaining that to me. Makes alot of sense now. And the only reason I would like them to use my box as the SMTP server is so they can send mail to people under @high-on-linux.net .

Ok, I made a mynetworks file and in it I put the exact IP of someone that wants to use it. Will this work? They dont really have a hostname, more like PlanW-176-xxx-xxx.pompano.net. I have no problem manually putting in the few IPS I will need to, like I said it wont be more that probably friends and family . Thanks again!