Right, I'm sure this is a networking problem, so here goes.
I have a domain, (domain.com) hosted at an external host. So they have a mailserver (mail.domain.com). I decided I wanted to handle mail myself on my own mailserver (home.isp.com) so I ask my hosts to add an MX record for domain.com pointing at home.isp.com, with mail.domain.com being a backup.
The network configuration at home.isp.com is a cisco 837 which allows smtp in, and a static forward to send any smtp traffic to the mailserver on the inside:
ip nat inside source static tcp 192.168.0.2 25 interface Dialer1 25
Then I install postfix on the mailserver inside at home, and try to get it working. Every time I try to send a mail locally (sendmail -bv root) the error logs I get from postfix are:
Ok, so here, it's trying to connect to home.isp.com on port 25, and that's resolving to the external ip address and is being blocked, so it moves onto the next mailserver which is successful. For whatever reason, whilst port 25 is open to the outside world on my ip, I can't telnet to it from inside the network indicating that something's blocking it. At first, I thought to just add a hosts file entry pointing it at the localhost, but that didn't work, it still reports the external ip address in the logs.
The next step, is to figure out how to get the router to take traffic from inside the network pointed at it's external ip address, and get it to follow the rules properly. Either that, or do something funky with the routing on the mailserver.
Any ideas?
I have a domain, (domain.com) hosted at an external host. So they have a mailserver (mail.domain.com). I decided I wanted to handle mail myself on my own mailserver (home.isp.com) so I ask my hosts to add an MX record for domain.com pointing at home.isp.com, with mail.domain.com being a backup.
The network configuration at home.isp.com is a cisco 837 which allows smtp in, and a static forward to send any smtp traffic to the mailserver on the inside:
ip nat inside source static tcp 192.168.0.2 25 interface Dialer1 25
Then I install postfix on the mailserver inside at home, and try to get it working. Every time I try to send a mail locally (sendmail -bv root) the error logs I get from postfix are:
Code:
Feb 19 00:51:22 tickle postfix/smtp[8952]: connect to home.isp.com [84.***.***.***]: Connection refused (port 25)
Feb 19 00:51:22 tickle postfix/smtp[8952]: EB2C46E8FDD: to=<[email protected]>, orig_to=<root>, relay=mail.domain.com[83.***.***.***], delay=8, status=deliverable (delivery via mail.domain.com[83.***.***.***]: 250 2.1.5 <[email protected]>... Recipient ok)Ok, so here, it's trying to connect to home.isp.com on port 25, and that's resolving to the external ip address and is being blocked, so it moves onto the next mailserver which is successful. For whatever reason, whilst port 25 is open to the outside world on my ip, I can't telnet to it from inside the network indicating that something's blocking it. At first, I thought to just add a hosts file entry pointing it at the localhost, but that didn't work, it still reports the external ip address in the logs.
The next step, is to figure out how to get the router to take traffic from inside the network pointed at it's external ip address, and get it to follow the rules properly. Either that, or do something funky with the routing on the mailserver.
Any ideas?
