Sorry to be a party pooper, but the SMTP proxy in Astaro is NOT intended to be used with a SMTP server external to your network. I asked this question more than once in the certification training, and it was clearly explained that the SMTP proxy is intended to be used in FRONT of your own mail server on your network. In other words, you set your public DNS MX record to point to the Astaro box, the Astaro proxys and filters all the inbound SMTP mail and ships it off to your server inside your network. That way, your mail server is never exposed directly to the Internet and everything going to it is prefiltered for spam and viruses.
Sorry to be a party pooper, but the SMTP proxy in Astaro is NOT intended to be used with a SMTP server external to your network. I asked this question more than once in the certification training, and it was clearly explained that the SMTP proxy is intended to be used in FRONT of your own mail server on your network. In other words, you set your public DNS MX record to point to the Astaro box, the Astaro proxys and filters all the inbound SMTP mail and ships it off to your server inside your network. That way, your mail server is never exposed directly to the Internet and everything going to it is prefiltered for spam and viruses.
