I am implementing an Internet Security and Acceleration (ISA) firewall on my network. I want to know the protocol (ESMTP or SMTP) port to open to allow my ISP Linux server to relay mail to my Linux server across the firewall.
If anyone may help.....!!!!

First you need to make sure your ISP has an entry in there DNS server for your SMTP servers IP address. "Known as the MX address"
If they haven't set this then nothing will know where your SMTP server is for the @domain address.

If this is done then you'll need to allow inbound connections from anywhere to your SMTP servers port 25.
"inbound mail won't just come in from your ISP's SMTP server as the MX addresses is a pointer for anyone's domain to send you mail directly.

If your ISP hosts the mail for you then that's a completely different set of rules. "i.e you login to a pop server at the ISP and forward from your MTA to it's SMTP outbound server"

Someone correct me if I'm wrong, as I haven't done this for awhile.

/Raz

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tbhebe has reported this post:


This is part of this thread:
Implementing an ISA firewall
http://www.linuxquestions.org/questi...?threadid=9381

This is the reason that the user gave:
The MX records are already set to point to my linux box. its been working without the firewall.
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tbhebe,
Only report posts if you have a problem with something.

As I said if you read my post fully:
"If this is done then you'll need to allow inbound connections from anywhere to your SMTP servers port 25. "
That's the rule for the firewall.

/Raz