sendmail relay
 

Hi

I have two ISP running. How can I relay my mails to the second ISP machine so that mail goes out even when the first isp is down (which is on the same LAN) after some time only if my first ISP is down.
I use redhat enterprise version and sendmail running on it.
Can it be relayed by sendmail after a interval say after 5 min.

Sanjib Gupta

Easiest method is to configure DNS MX records to perform this - if one email server is down the secondary MX record take effect. In one of the domains you setup the email server for that domain as an MX record with a lower number and the other domain's email server as a higher MX record number - reverse for the other domain... Check out the docs for dns and mx records to see how this is done...

You will also need to setup the email servers to allow the each others domain to relay but block any outside email from being able to relay through the email servers (don't want to add to the spam issues do you?)...

gm...

Thanks for your reply.
can you please tell me how do i setup email server so that the mails will be automatically routed through the other server when one isp is down(over lan as the machine is in the same lan).
Sanjib Gupta