What if their exchange servers VPN'd into your mail servers? You could use the private ip.
-Jon ----- Original Message ----- From: Darin Cox To: [email protected] Sent: Friday, August 17, 2007 12:24 PM Subject: Re: [IMail Forum] being a smart host without being an open relay You have two main options 1. Have them get a static IP, or 2. Have their Exchange server POP the messages from your server. Unfortunately, Exchange POP connectors cannot be configured to POP more frequently than every 15 minutes. That said, if they are using a dynamic DNS (DDNS) service, you could configure your server to relay to a hostname that is continually updated with the current IP via DDNS. Their may be some delays when the IP changes, depending on how quickly the DDNS is updated, and the TTL on the records. By far, the best solution is for them to spend a little more, and get a static IP. Darin. ----- Original Message ----- From: Adam Greene To: [email protected] Sent: Friday, August 17, 2007 11:47 AM Subject: [IMail Forum] being a smart host without being an open relay Hi! We're being approached by a networking company whose customers need Smart Host services. i.e. they run Exchange servers and are being blacklisted because some of the Exchange servers are assigned dynamic IP addresses. They want the Exchange servers to relay through us, so as not to get blacklisted. I don't quite understand how they could even be receiving email reliably with a dynamic IP address on their mail server; I'm checking with the networking company now. Maybe they're using some kind of dynamic DNS service? Anyways, I'm thinking about how to provide this service without becoming an open relay. I need the Exchange server to authenticate to Imail somehow. There's also the issue of outbound port 25 being blocked by many major ISP's. We've toyed with the idea of requiring SSL connections on port 465 from the Exchange server, but I'm not sure of what kind of server-to-server authentication I can set up in Imail to prevent us from becoming an open relay. Is someone else already doing this with Imail? What solution have you come up with? Thanks, Adam
