Sender Based Routing Agent for Exchange Server | ExSBR

Multi-Tenancy Software for
Microsoft Exchange Server

Sender Based Routing Agent for Exchange Server

messageconcept ExSBR, the Sender Based Routing Agent for Exchange Server

  • routes your mails easily by sender’s SMTP domain and AD group memberships
  • fully integrates with Microsoft’s management tools of Active Directory and Exchange Server
  • is scriptable from the PowerShell command line
  • is configured centrally for your Microsoft Exchange Server Organization
  • scales from Small Businesses to Global Enterprises

messageconcept ExSBR is a routing extension for
Microsoft Exchange Server 2007, 2010, 2013 and 2016
with Hub Transport and Edge Transport server roles.

The emails of over 500,000 satisfied users worldwide are routed with ExSBR.

Reference Customer

“We rolled ExSBR into our production environment last night, and the results have been nothing short of amazing. If you ever need a reference, please feel free to give them my name.”

Rod Newcomb, Hosted Services Engineer, LightEdge

Microsoft Platform Ready for Exchange Server

messageconcept ExSBR passed the Microsoft Platform Ready test for Exchange Server:

Microsoft Platform Ready for Exchange Server

Practical Applications

Typical Usages of messageconcept ExSBR

Sender Based Routing is needed in very different scenarios. A few examples might help you to understand the role of messageconcept ExSBR in our customers’ Exchange Server environments:

Usage by Internet Providers

Hosting providers and ISPs use ExSBR to route mails of certain customers to domain-specific smart hosts. This is the easiest way to avoid being filtered by recipient’s junk mail filters.

Connection to Encryption-Gateways

Some customers use ExSBR to route the mails from certain senders only to an encryption gateway. This might save license fees for the encryption solution or reduce the gateway’s hardware and/or availability requirements.

Send as a Partner’s Domain

Companies use ExSBR to route mails for specific mailboxes hosted in their Exchange Organization to a partner’s SMTP gateway. In this case ExSBR allows hosting of “foreign” mailboxes of a partner’s organization for example.

Delivery of Newsletters

Marketing departments use ExSBR to route their newsletters to an alternate gateway. This helps to avoid huge traffic load on the regular SMTP routes. And even if your newsletter gateways get blocked by anti-spam black lists, your production messages will not be affected.

Usage by Authorities

Authorities match regulative requirements of local law to route specific mails to a secured authority network instead of the internet. A good example are the Government Code of Connections for the Government Secure Extranet (GCSx CoCo) or the Public Services Network (PSN CoCo) in the United Kingdom.

Freemail-Addresses in Exchange

Small businesses often host free mail addresses such as Gmail, 1&1, GMX or in their Exchange organization. ExSBR helps to route their mails to different connectors which authenticate on a per-user basis.

Control of external Communication

ExSBR is very useful in scenarios where companies distinguish between users who are allowed to send mails internally only to specific partners or to the entire internet.

Limitation of Message Sizes

Other companies use ExSBR to allow different message sizes for specific user groups by implementing restricted SMTP connectors.

Communication with De-Mail, E-Zorg, MSSanté and PEC

Businesses may be forced to use encrypted or signed mails in the communication with authorities or other companies. In Italy the Decreto-legge 29 novembre 2008, n. 185, articolo 16: “Riduzione dei costi amministrativi a carico delle imprese” for example regulates the use of “Posta electronica certificata” (PEC). Here, ExSBR routes the mail to the secure SMTP server of PEC. ExSBR also works successfully with E-Zorg in the Netherlands or MSSanté in France at our healthcare customers.

Further Scenarios


Didn’t find your situation in our examples?
Still not sure if messageconcept ExSBR is the right solution for you?

Contact us to benefit from our consulting.

Success Story

Multi-tenancy with messageconcept ExSBR in active logistics’ European data center

Our customer active logistics is the European market leader in vertical software solutions for the logistics market. Their software builds and controls logistics chains and organizes large cargo networks. They operate two independent data centers, close to the headquarters and central hubs of several cargo networks in Niederaula in the heart of Germany.

In late 2008 active logistics’ managing director Michael Otto raised two major challenges: “We wanted to unify and consolidate the infrastructures of all subsidiaries. On the other hand our customers wanted us to take the overall responsibility for the ICT operations for our software solutions from a managed desktop to our host systems. Our solutions offer great advantages, especially because we are able to operate the complete ICT infrastructure of our customers.” While the central multi-platform ERP infrastructure supported multi-tenancy from the early beginnings, active logistics was not able to offer the same in the Windows based infrastructure.

The solution was to centralize and standardize the Windows environment. Besides the introduction of central file services and a managed desktop, active logistics implemented a multi-tenant and highly available Exchange Server infrastructure. “We now offer our customers and subsidiaries additional services and are able to reduce manpower requirements at the same time.” says Michael Otto. In Exchange Server active logistics implemented messageconcept ExSBR to control the routing paths of customers’ emails. The customer decided to use ExSBR in Domain Routing mode for most customers. With this configuration, the data center is able to route emails of an entire tenant e.g. to a mail server in the tenant’s on premise infrastructure or to a cloud based service.

Michael Otto

“We have been using ExSBR for five years now. The software proved to be a powerful and very reliable solution for us.”

Michael Otto, Managing Director, active logistics

If a customer needs to route just a subset of users to a specific gateway, the configuration can be altered by creating an exception based on ExSBR Group Routing. This is used e.g. to route certain user groups to encryption or archiving gateways.

ExSBR enables active logistics to design the routing scenarios based on the needs of each specific customer. By configuring the Microsoft components as well as ExSBR from PowerShell even the initial setup of a new tenant can be done in the blink of an eye.

“We have been using ExSBR for five years now. The software proved to be a powerful and very reliable solution for us.”, Michael Otto concludes.


Our software routes emails at many public institutions, IT providers and companies. The following list represents typical examples of our software customers.

Routing by sender’s SMTP domain

messageconcept ExSBR changes the Exchange Server default routing. On hub and edge transport servers emails will be routed to different Send Connectors according to the sender’s domain name. The software makes it possible to setup message routes for different Internet providers or networks.

This is the most common usage scenario for multi-tenant environments.

Routing by sender’s Active Directory group memberships

On hub transport servers emails will additionally be routed according to sender’s group memberships in Active Directory. ExSBR enables you to choose different Send Connectors for specific users or user groups.

messageconcept ExSBR even supports nested groups. Therefore you are able to do a role based administration of ExSBR by putting your existing groups into the specific ExSBR groups in Active Directory Users and Computers.

As AD group membership is not available in the ADAM directory of edge transport servers, ExSBR uses its own local ExSBR Edge List configuration on edge boxes to distinguish message routes for individual accounts.

Fast and easy installation

The software is installed by registering and enabling ExSBR as a Hub Transport agent in Exchange Server. Installation and configuration are usually completed in less than 15 minutes.

Integration with Microsoft’s management tools

messageconcept ExSBR is managed with the default Microsoft management tools. There is no need to install additional software to manage the ExSBR rule set. messageconcept ExSBR is maintained with Microsoft Exchange Management Console.

Alternatively, all configuration options can be automated in Microsoft Exchange Management Shell (Powershell). This allows providers to integrate the ExSBR ruleset creation in their configuration panels.

Central configuration for your organization

messageconcept ExSBR integrates natively with Microsoft Active Directory. The ExSBR rule set is stored in the Active Directory configuration partition. All ExSBR installations in your organization can share one configuration.

No need to invest in separate mail systems or gateways

With messageconcept ExSBR you no longer have to invest in dedicated mail systems for specific usage scenarios. It allows the independent hosting of several customers or SMTP domains inside one Exchange Server organization.


The software was originally designed for large hosting providers and enterprise organizations with a huge number of mailboxes and a high amount of mail traffic. Customers usually run messageconcept ExSBR in configurations from one to four and even more concurrent hub transport servers.

With the introduction of the limited ExSBR Business Edition licenses in 2010, messageconcept satisfies the need of small and medium businesses for sender based routing functionality in Exchange Server as well. Single server organizations with a limited number of mailboxes benefit from this license option.

Technical Specifications

System Requirements

Operating System Windows Server 2003 (R2)
Windows Server 2008 (R2)
Windows Server 2012 (R2)
Exchange Server
(64 Bit only)
Exchange Server 2007
Exchange Server 2010
Exchange Server 2013
Exchange Server 2016
Exchange Server Roles Hub Transport Server
Edge Transport Server

Further Requirements

Please note that the following requirements apply:

  • Microsoft .NET Framework 2.0 SP1 is required.
  • ExSBR needs to be installed on all Transport Servers with external Send Connectors.
  • ExSBR supports all setup types, e.g. the /Hosted Mode.
  • All system requirements of Microsoft Windows Server and Microsoft Exchange Server apply.
  • Please see the Exchange Server Supportability Matrix in Microsoft TechNet for more information on supported operating systems for different Exchange Server versions, service packs and updates.

Our customer support team would be happy to check the requirements in detail with you before evaluation or purchase.

SBR in mixed/legacy Exchange Organizations

Exchange Organizations with Exchange Server 2007, 2010, 2013 and 2016, work exactly like Organizations with just one of these versions only. But if you mix these versions with legacy servers before Exchange Server 2007 in your Exchange Organization, some specialities need to be recognized.

If you are in a migration process from legacy Exchange Server versions to Exchange Server 2007 or higher, please upgrade your internet facing bridgehead servers based on Exchange Server 2000/2003 to Hub Transport Servers based on Exchange Server 2007 or higher prior to implementing messageconcept ExSBR.

If you have any questions regarding messageconcept ExSBR in a mixed environment, please contact us directly to profit from our long-term migration experience.

SBR in legacy Exchange Server Versions

messageconcept ExSBR runs on Microsoft Exchange Server 2007 and higher only. If you are running a legacy Exchange Server version in your environment you need to at least upgrade your Internet facing transport servers to Exchange Server 2007 or higher to run ExSBR. An upgrade of other servers and roles is not needed.

Alternatively make use of the built-in Delivery Restrictions functionality on your SMTP Connectors. This feature is available in Microsoft Exchange Server 2003, Microsoft Exchange 2000 Server and older versions; it is not a part of Exchange Server 2007 or higher.

This functionality is turned off by default, because it significantly affects system performance. For more information please see this Microsoft Support KB Article.

After a migration to Exchange Server 2007 or higher messageconcept ExSBR is your solution for sender based routing.

Software Licensing

ExSBR Licensing

messageconcept ExSBR will be installed on every internet facing Hub Transport or Edge Transport server with external Send Connectors. One license is needed for each server ExSBR is installed on. Per default you would purchase one license for each hub transport server.

If you are using Exchange Servers with edge transport role, you usually would install ExSBR on these servers only, instead of installing our product on your hub transport servers.

If you are using hub transport servers without any external SMTP connectors, you don’t need to install ExSBR on these servers and certainly you don’t need licenses for these internal servers.

Compare the different ExSBR licenses and prices on our pricing site.

Maintenance: Support and Software Updates

Optional maintenance subscription includes unlimited support and all minor and major software updates released during term of maintenance contract.

Support will be provided in English and German language. Our hotlines are available 24/7. Outside European business hours, our call center will arrange a callback of a qualified technician for you within the business hours of your time zone.

Evaluation Version

We offer an unlimited trial version to evaluate messageconcept ExSBR in your test or production environment for up to 30 days. Please use our download page to get a free eval version matching your requirements.


For current customer, please contact our sales team if you need a quote for an upgrade to a higher edition or addtional server licenses.