Smarthost your outbound mails to the isp's smtp servers. Request both isp to allow relay for both of your links From: skunkworks-bounces@lists.my.co.ke [mailto:skunkworks-bounces@lists.my.co.ke] On Behalf Of Simon Mbuthia Sent: Friday, February 25, 2011 1:38 PM To: Skunkworks forum Subject: [Skunkworks] Send mail from 2 internet links Hi guys, I happen to be on two ISPs [therefore two public IPs. My mail server uses an ISP [ISP-A] whose link which has been annoyingly erratic since yesterday. I wish to route my outgoing emails through the other ISP [ISP-B], but some servers reject our mails when we use that link due to inconsistent PTR records. What I mean is this: mail.mydomain.co.ke resolves to my ISP-A [public] IP address. When I route to ISP-B, the EHLO message would show a connection coming from mail.mydomain.co.ke, but the PTR would not be equal to the IP given by ISP-B [from which the email actually originates] and that is why some mail servers drop the connection at that point. Now my question: Is there a way I can combine dvert traffic to go out through my ISP-B box such that traffic appears to be from ISP-A? I tried using SNAT yesterday and it didnt work. Experiment: I was also wondering whether it is possible to route traffic based on the destination port, i.e. my mail and squid proxy server is 192.168.80.1/24 and also has 172.16.10.2/29. The ISP-A box is 172.16.10.1/29 and ISP-B is 172.16.10.3/29 [not their real IPs :-P]. I would like to make the default gateway for my mail and internet server 172.16.10.3, but route outgoing SMTP only traffic through 172.16.10.1. I know port numbers are dealt with in the transport layer while routing is a lyer 3 affair, but Ibelieve all things are possible in computing. I would appreciate your ideas, suggestions, criticisms and even blank replies as are normally sent by some. Me.

On Fri, Feb 25, 2011 at 13:38, Simon Mbuthia <simon.mbuthia@gmail.com>wrote:

Hi guys,

I happen to be on two ISPs [therefore two public IPs. My mail server uses an ISP [ISP-A] whose link which has been annoyingly erratic since yesterday. I wish to route my outgoing emails through the other ISP [ISP-B], but some servers reject our mails when we use that link due to inconsistent PTR records. What I mean is this: mail.mydomain.co.ke resolves to my ISP-A [public] IP address. When I route to ISP-B, the EHLO message would show a connection coming from mail.mydomain.co.ke, but the PTR would not be equal to the IP given by ISP-B [from which the email actually originates] and that is why some mail servers drop the connection at that point.

Now my question: Is there a way I can combine dvert traffic to go out through my ISP-B box such that traffic appears to be from ISP-A? I tried using SNAT yesterday and it didnt work.

Experiment: I was also wondering whether it is possible to route traffic based on the destination port, i.e. my mail and squid proxy server is 192.168.80.1/24 and also has 172.16.10.2/29. The ISP-A box is 172.16.10.1/29 and ISP-B is 172.16.10.3/29 [not their real IPs :-P]. I would like to make the default gateway for my mail and internet server 172.16.10.3, but route outgoing SMTP only traffic through 172.16.10.1. I know port numbers are dealt with in the transport layer while routing is a lyer 3 affair, but Ibelieve all things are possible in computing.

I would appreciate your ideas, suggestions, criticisms and even blank replies as are normally sent by some.

You can actually (ab)use google mail service for this, as long as you configure your MTA properly. I will not provide details. That's your home work. -- Best regards, Odhiambo WASHINGTON, Nairobi,KE +254733744121/+254722743223 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Damn!!