Introducing Hurricane Load Balancer

Throughout our company’s history we have solved many of our in-house computing and infrastructure needs by building custom solutions when an adequate commercial solution was not available.  As we built out our hosted SMTP server solution we discovered we needed an adequately powerful SMTP load balancer to create the high availability network we desired. As we considered commercial solutions we found they were inadequate for our needs so the Hurricane Load Balancer was born.  We’ve been successfully running Hurricane Load Balancer in our own hosted service for over a year and it has performed flawlessly.  Today we are announcing the availability of this great new product to the general market for purchase as part of our on-premise Hurricane product family.

The Hurricane Load Balancer (HLB) is a windows service that distributes SMTP traffic between one or more Hurricane MTA servers. This allows existing and new MTA customers to balance traffic, achieve greater fault tolerance and add capacity with minimal effort. The most common reasons for using a HLB include:

High Availability

In addition to being able to seamlessly handle an MTA instance failure, the HLB configuration settings can be changed dynamically without requiring a restart. Adding and removing nodes, IP addresses, and ports can be done at any point with no downtime.


Because of the event-driven non-blocking I/O design of the LB it can easily handle hundreds of connections per second and thousands of simultaneous connections in a virtual environment. This means if you are currently getting 1 million message an hour with a single MTA, utilizing 3 MTA’s would allow you to process 3 times that much while still setting your application to submit to a single endpoint.

Real-Time Node Failover

Standard load balancers utilize a “heartbeat” check that pings each node and removes nodes from the cluster when a check fails. A common problem with this process is that connections are lost in the time between the node going down and the heartbeat detecting the failed node. This problem is resolved with the HLB as it detects connectivity problems in real time. If the HLB can’t connect to a node, it will continue to try each additional node until a connection can be made.

IP Address Preservation

Since the HLB communicates to the MTA using a proprietary protocol it can preserve the IP address, which allows the MTA to show the client’s IP address in the logs and headers instead of the LB’s IP address. This makes debugging multiple clients and setting up inbound restrictions/black listings based on the IP address possible.

SSL Termination

The HLB can allow SSL/TLS encrypted connections on one or more defined ports and route those to the MTA.

The Hurricane Load Balancer enables existing and new Hurricane MTA Server customers to deploy an effective high availability SMTP server network.  It is available now!  For more information about Hurricane Load Balancer please contact our sales department.

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