Free Trial

Safari Books Online is a digital library providing on-demand subscription access to thousands of learning resources.

  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL
Help

Chapter 13. Multiple Device Deployments > Email Availability with Multiple ESAs

Email Availability with Multiple ESAs

If a single ESA meets an organization’s capacity needs, continues to run fault-free, has uninterrupted power and network connectivity, that single appliance will provide reliable service and deliver clean email traffic. What happens if all these conditions aren’t met?

When discussing an environment of multiple ESAs for the purpose of additional capacity, or reliability in the event of failure, we’re really discussing architecture. Multiple ESAs can be configured to fit into a load-balanced or redundant SMTP architecture. Note that this is different than saying that the ESAs support load balancing or failover natively—they don’t. Each ESA is its own distinct appliance that does have hardware and network features for redundancy, but does not provide a true means of sharing load or automatically failing over to another appliance. However, if we design an ESA deployment correctly, we can get these capabilities without too much effort or additional cost.


  

You are currently reading a PREVIEW of this book.

                                                                                                                    

Get instant access to over $1 million worth of books and videos.

  

Start a Free 10-Day Trial


  
  • Safari Books Online
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint