We're excited to introduce SmarterMail High Availability, or “SmarterMail HA”. SmarterMail HA is the first economical and scalable Exchange-level mail server that's perfect for corporations, enterprise organizations, and small to medium businesses. In addition, it's ideal for ISPs, MSPs, and hosting providers looking to offer a true Exchange alternative for an almost infinite number of domains and users.
Benefits of SmarterMail HA
SmarterMail HA extends all the features and functionality of SmarterMail while allowing for an unlimited number of users and domains across interconnected hubs, nodes, and centralized storage, making email services completely fault-tolerant.
If a business wants to host a million domains, SmarterMail can help achieve that goal. If a business wants to offer millions of free email accounts using a single domain, SmarterMail allows for splitting that domain and its users across the entire cluster. If a business wants to offer a ton of domains and/or a combination of large single domains and lower-tier mail services along with premium mail services across these domains and users, SmarterMail HA can help you do that as well.
The point is, a business can have multiple hubs and nodes, a single hub and multiple nodes, or even one hub with one node. The architecture is purely based around need. The beauty of it, however, is that there is no set requirement: SmarterMail HA can expand or contract as needed.
Architecture of SmarterMail HA
Speaking of "hubs", "nodes" and "centralized storage", perhaps some explanation of the components that make up SmarterMail HA is in order.
SmarterMail Nodes are very similar to the standard SmarterMail installations that customers and administrators are familiar with today. SmarterMail Hubs are servers that proxy all authentication and content to and from SmarterMail Nodes, so they know which domains and users are on what nodes. The hubs are responsible for knowing where everything is on the cluster, and it's where administrators can view the status of all nodes, and node health. Hubs are also responsible for bringing standby nodes online to self-heal the customer and continue providing mail services to users.
Then there's Centralized Storage. This is a crucial component for SmarterMail HA. SmarterMail offers a number of ways to efficiently use both slower and more performant storage so that you can cost-effectively build out your SmarterMail HA hubs and nodes. It allows both hubs and nodes to have access to consistent and synchronized data, and provides a critical layer of data integrity and redundancy to the high availability installation.
Deployment and Flexibility
Flexibility was a key component we worked towards when planning and eventually programming SmarterMail HA. Administrators can start with a 1 hub / 1 node roll out, and then start adding hubs and dodes, add incoming/outgoing gateways, offload spam and virus checks, drop load balancers in front of the hubs, have standby hubs and nodes ready as needed, and more. It’s truly built with flexibility in mind — administrators can basically build out their deployments as they see fit, then allow them to grow to fit the needs of their business.
Pricing
Even though SmarterMail offers more features than most of the leading mail servers on the market, it costs far less than all of its competitors. Even with that, building a huge cluster could be expensive (hardware and software), so SmarterTools offers SmarterMail HA as a monthly cost to its partners, and the monthly cost is based on usage during that month. This allows customers to build SmarterMail HA dynamically as their business grows and their needs change. Hubs and nodes can expand and contract, and the cost of SmarterMail HA adjusts in the same way.
Rollout and Availability
UPDATE: SmarterMail HA was officially released on July 10, 2025. If you would like additional information and/or would like help planning your environments or migrations, please contact our sales team (sales@smartertools.com) and we will be happy to help.
If you're interested, we have a downloadable PDF that demonstrates the potential architecture of SmarterMail HA. It's a more complex architecture that includes incoming and outgoing gateways, remote antivirus and antispam, a demonstration of standby Nodes, and more. That said, this is just one example of how SmarterMail HA can run.