Can somebody help set up mail server on Centos 5 + postfix + dovecot

[treeman]

Hi, I am practicing on setting up a mail server at home before i go get a business plan and set up a real thing. So far this is what I have done:

1. Register a domain
2. Make a fresh install of centos 5, dovecot, postfix, squirrellmail.
3. This is what I have done on my domain host:
* * Domain Record A <wanip> -> <nat> -> <centosbox> (I can telnet on port 110 through my domain and get dovecot welcome message so i assume this is functioning ok)
* * Set my domain name as a MX record, using host command it resolves to my wan ip, and using dig <domainname> MX seems to look ok too
4. Made sure there is no email forwarding etc
5. Using my isp smtp for outgoing mail since port 25 is blocked in and out, but 110 is open.

I can send mail on my internal network and receive it. I can send mail out to outside, but I can't receive from outside. There is no immediate bounce back but after a while I get email delayed.

I am not too experienced with mailservers so I am not sure what I am doing wrong, I thought since the mx record is sersolving to my wan which in turn redirects to internal ip and port of pop3 it should work

Any help or tips suggestions or observations on the topic would be much appreciated as the last few days I have been scanning forums and trying to absorb as much on the topic as possible. Cheers

[matey]

sorry for replying but I was just wondering if port 25 is blocked can you use localhost ( 127.0.0.1 )as the receiving end?

[dzudzu]

your postfix might not be set as appropriate reciver. How about posting logs for /var/log/maillog and in same time post postconf

[treeman]

Ok I had some help and it looks like the problem is my isp blocking port 25 in and out, port 110 is not for receiving mail just for checking the inbox.
So thats that no more testing on this isp. But would it work if i put in my isp mailserver for mx record on my domain? So emails sent to user@domain.com would go to user@isp.com ? I am trying to get as much testing and learning done as possible on my limited residential isp plan. I don't want to buy a business plan just for testing at this stage.