Change listen address for SMTP Relay

[jainoxi]

I have a Astaro box, which I use, amongst others, for SMTP Relay.

I have bound two public addresses (1.1.1.1 and 1.1.1.2 as an example). The first address is being used for VPN, end user portal, and proxy/firewall.

The second address is bound as a secondary address to the same interface as the first address. So far so good, everything works as can be expected.

However, using the SMTP Proxy, I found that the Astaro box only binds SMTP to the first address (1.1.1.1), but not the second. So connecting to the first address with telnet port 25 is no problem, but connecting to to port 25 on the second address is a no-go.

Since my MX records are refering to the second address, I'd like to see that port 25 is connectable on the second address (and consequently, not on the first). How do I accomplish this?

(A different solution would be to change the MX record from the second to the first IP Address, but that's just not as fancy )

[has]

the outbound traffic gets the Ip address of the interface which has default gateway defined.

You have two ways to solve this , define your MX record as the primary interface with default gateway and the others as alias or

Create SNAT rule fro SMTP
source External Address with Deafult gaetway
dest any
service smtp
change source to your second IP (MX record)