Typical Architecture
A slightly more typical architecture (FIGURE 3-3) more commonly found adds a couple of SMTP relays to the simple configuration.
Figure 3-3. Alternate Configuration With SMTP Relays and Firewall
Often one relay is configured as inbound and the other outbound. These relays off-load the routing and rejecting of messaging. These relays can also run antivirus and antispam software. This configuration assumes that the only protocol coming from the Internet or going out to the Internet is SMTP. Users access the messaging system internally only, through a virtual private network (VPN) or through the firewall.
Combining a simple messaging ...
Get Sun™ ONE Messaging Server: Practices and Techniques for Enterprise Customers now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
