Email Servers / Public IP Addresses

wen · ‎05-27-2010

We have 4 email servers behind a Cisco ASA Firewall.

All 4 email servers have an internal ip address and their own unique public ip address.

For example)

Internal Public

EmailServer 1 192.168.13.2 1.1.1.2

EmailServer 2 192.168.13.3 1.1.1.3

EmailServer 3 192.168.13.4 1.1.1.4

EmailServer 4 192.168.13.5 1.1.1.5

Since it is behind the firewall, regardless of which email server we send from, the receiving email server sees all coming from the same public ip address(1.1.1.6) .

How do we set it up so that if we send emails from emailserver 1, the receiving email server will see 1.1.1.2 instead of 1.1.1.6? This goes the same for the other 3 email servers.

Thanks

Jon Marshall · ‎05-27-2010

wen@realitydigital.com
We have 4 email servers behind a Cisco ASA Firewall.
All 4 email servers have an internal ip address and their own unique public ip address.
For example)
                         Internal              Public
EmailServer 1     192.168.13.2      1.1.1.2
EmailServer 2     192.168.13.3      1.1.1.3
EmailServer 3     192.168.13.4      1.1.1.4
EmailServer 4     192.168.13.5      1.1.1.5
Since it is behind the firewall, regardless of which email server we send from, the receiving email server sees all coming from the same public ip address(1.1.1.6) .
How do we set it up so that if we send emails from emailserver 1, the receiving email server will see 1.1.1.2 instead of 1.1.1.6? This goes the same for the other 3 email servers.
Thanks

Wen

It shouldn't do that. When you say each e-mail server has it's own public IP have you setup statics ie.

static (inside,outside) 1.1.1.2 192.168.13.2

static (inside,outside) 1.1.1.3 192.168.13.3

etc..

Jon

wen · ‎05-28-2010

Hi Jon,

Thanks for the reply.

I have the way setup as you suggested. I thought the same too.

I subscribed to AOL whitelist, and they see it coming from 1.1.1.6 instead. It doesn't matter which email server I am using.