I have two Exchange servers with Single Domain and two public ip addresses from two ISP given so that both can act as SMTP server for outgoing mails. Now whenever one of my ISP is down, the mails sent to external world are bouncing for one mail server mailboxes stating that PTR record does not exist for the IP. This is because the ip what it takes is the Firewall IP to the external world.
What we need is, whenever any one ISP line is down, that particular Exchange server to which we assigned this ISP public IP, should route all the external mails through other Exchange. This is currently not happening. It still sends the mails through its own smtp server which takes our Firewall IP to external domains and return it with PTR record error.
For this to happen, do i need to create a seperate SMTP Relay on demand basis? or any seperate send connector for this will do the job?? Will exchange not automatically route the mails to other exchange server by default ? or will smart host routing is the way ? (I tried this by adding the server in SMTP connector but still it bounces).
Any help is appreciated.
regards
Sundar
regards Sundaresan.C