We are hosting Lotus Domino Mail Server in our office with public domain. Live ip is configured on main gateway router. When any email from the internet arrives , it comes to our gateway router public ip, & router rules forward port 25 requests to domino server.
& when lotus user sends email, it delivers to domino server, and since the domino server have default gateway pointing to the gateway router, it simply sends email directly to the recipient. this is quite simple till now.
Now we have acquired Barracuda Antispam hardware device (model 300a) & as per the local barracuda vendor they are asking us that we must have SMTP relay server at our end in order to route user outbound emails from barracdua to the internet.
so If we remove barracuda from the picture, we dont need the smtp relay, and if we put barracuda why we need SMTP relay ? to send outgoing email, I can bypass barracdua simply right? because domino is using my gateway router as default gateway?
we dont want to relay emails to ISP SMTP relay because there public IP sometimes gets blacklisted this is why we want to use our own public IP.
So what should I do in this regard?