Hello,

I have a linux box running Fedora Core 4 as a web/email server (webserver works great). I am having problems configuring the email server. I am using postfix, dovecot, and squirrelmail. I am able to send messages from both outlook and squirrelmail to any email address as my ISP is filtering port 25 and I have configured postfix to just use my ISP's outgoing mail server.

My problem is my mail server isn't recieving mail from outside domains (I can send and recieve mail with addresses @mydomain.com). I have tried to connect to the mail server with outlook express and It won't connect, unless I point the incomming mail server to the private IP address of the server. Below is the error message that I get.

"The server responded with an error. Account: 'email.mydomain.com', Server: 'xxx.xxx.xxx.xxx', Protocol: POP3, Server Response: '-ERR Cannot connect to POP server xxx.xxx.xxx.xxx (xxx.xxx.xxx.xxx:110), connect error 10060', Port: 110, Secure(SSL): No, Server Error: 0x800CCC90, Error Number: 0x800CCC90"

My router is forwareding ports 25 and 110 to my server, no other firewall exists on my network.

Sounds to me that my postfix config file needs some tweaking. Any help will be greatly appreciated.

Thanks in advance!!!

I'll admit to being a little confused here, but I assume you can send/receive mail on your internal network, but not receive from outside.

Postfix is sitting there listening on port 25 for incoming mail, so if your ISP has it blocked, it won't be able to receive external mail any more than it can send it.

When you send email externally, I guess you are relaying through your ISP's mail server - is that correct?

On the connect side, I'd expect you would need to use the private IP. Even without port blocking, trying to connect to you public IP probably won't work, as the name resolution doesn't work properly going out and back in (poor description, but I know it won't work for me and it's a long time since I read the explanation).

Sounds like your config is OK


Bill

That error could mean anything. First of all, unless you want to use a numerical IP address, you need to get a domain. Outside mail servers have no idea where you are by what you named your email server. You actually need to be listed in a DNS server. Then, like everything else on the whole internet, the external mail servers can go to the DNS server, look up your numerical IP, and send the mail to you. This isn't magical. You can get free domains for dynamic IP's all over the place. http://www.ods.org/ is a good one. It actually costs money, but you can go change the IP associated with your domain any time you want.

The internet does not work based on what you have named your email server. You have to have a DNS entry. This is how all domains work. You can name your server anything you like, but how does any other server know what that name means. Say my dynamic IP, via DHCP from my ISP, is currently 65.123.45.9. That's not what it really is, but let's just say. I need some way to tell the whole internet that 65.123.45.9 means 'mydomain.net' Me naming my server isn't going to do that. So, I need to go and get a domain, and tell whatever site registers the domain to tell the whole internet my server's name and the IP. I might not be able to get that exact name. I might have to call it AwesomeMachine.i13.org because every domain the domain service registers ends with i13.org.

OK, once this is done all the mail servers on the whole internet will be able to find your mail server because they will look on one of the many DNS servers on the internet and resolve your actual IP of 65.123.45.9. If your IP changes, you have to go back and change the IP associated with your domain registry. Just go to ODS and check it out.

Hello, matt8534, and welcome to LQ.

The error message you posted regards port 110, which is not related to postfix, which should listen on port 25. To test whether you can reach your mail server (not your POP3 server) from outside your network, you can try telnetting from the outside:
If you see a message like the following, then everything's fine:
In the above, ip.add.re.ss is your external IP address, i.e. the IP address assigned by your ISP.

If postfix doesn't answer as expected, then there are several possibilities:

1. your ISP is blocking port 25
2. your router isn't configured correctly to forward port 25
3. postfix isn't configured correctly

To test for the third possibility, log in to any computer inside your local network, possibly even the machine on which postfix is running, and try telnetting as above, but this time, use the postfix machine's (internal) IP address. If you still don't see the postfix greeting, then postfix isn't configured correctly and you need to read this and this. Otherwise, if you do get the postfix greeting, then it's not a postfix problem.