Designing Exchange Servers

The primary objective when designing an Exchange Server solution should be to meet the current and foreseeable business and technical requirements for the organization that will use it. Understanding the technical and business requirements of an organization is crucial to the success of the project. These requirements have to be explored and documented thoroughly, and revisited regularly during the design phase and implementation of the Exchange Server solution. Below are the business and technical requirements that should be taken into account. The relevance of these items will vary between organizations and projects.

Business Requirements

  • The total cost of the infrastructure, licenses, management staff & tools, and other costs should ideally be reduced when moving to a new Exchange Server infrastructure.
  • Implementation and administration time should be reduced.
  • Availability should be maximized.
  • Regular maintenance with zero downtime should be designed in.
  • The organization’s Regulatory Compliance and Legal Requirements should be met.
  • Existing business critical applications should be supported, or their functionality replicated.
  • Organizational growth should be easy to accommodate.
  • Data security and protection of organizational digital assets should be a core part of the design.
  • Data backup and recovery should be robust and easy.
  • Disaster Recovery should be a core design principle to allow for continuity in operations in the event of a disaster.

Technical Requirements

  • Deployment and administration should be automated where possible.
  • The different Mailbox requirements of the users should be accommodated, including those heavy users who require large mailbox sizes and anytime/anywhere access to their mailbox.
  • Multiple Clients Support – Outlook, Browser (OWA), mobile via 3rd party client apps.
  • High Availability, Disaster Recovery and inbuilt recovery of servers and databases.
  • Automated troubleshooting and alerting to catch potential problems early.
  • All in house and 3rd party applications and services that need messaging services, or other Exchange Server functionality, should be included in the design.
  • The Exchange Server design should support On-premise, Cloud and Hybrid deployment as required.

Understanding the Current Environment

Understanding the current messaging and application environment is critical when designing an Exchange Server solution. It is essential to understand every component of Exchange Server and its dependencies such as Active Directory. It is also essential to understand other components of the Microsoft Server stack that may be integrated with Exchange Server, for example Skype for Business, SharePoint Server, Office Online Server or any others that may be required. The items in the list below should be considered as part of the planning and design process:

  • Create and keep a current Exchange Architecture and network diagram. This helps everyone to understand AD sites topology, server deployments, site connectivity, IP Addressing and more.
  • Document Exchange Server versions with service packs and patch levels. Include the underlying Windows Server information as well.
  • Create and keep a current Exchange Configuration information document that lists the configuration settings and changes made.
  • Document the Exchange Server hardware/virtual model and configuration.
  • Document the Exchange Server process specification and utilization.
  • Document the Exchange Server memory allocations.
  • Document the Exchange Mailbox database configurations and size, including the number of databases on each server.
  • Document the Exchange Server storage design and the type of disks used for each server and database.
  • Document the high availability and disaster recovery model and procedures.
  • Include 3rd party vendor support documents and their escalation procedures for requesting support.

To assist in gathering some of the above information, reports can be generated using built-in Exchange Server tools. Below are some of the tools available to explore the current environment:

  • Microsoft Exchange Server Profile Analyzer
  • Exchange Environment Report
  • ExIISLogParser
  • Exchange Best Practice Analyzer

Understanding the Dependent Environment

Exchange integrates with many other products, and assessing any applications in use then designing to accommodate them is vital for a successful Exchange Server deployment project. All applications that will integrate should be listed and the integration methods documented. Below are some examples of applications and services to consider:

  • Active Directory
  • Mobile Device Management (MDM) Software
  • SharePoint Server
  • Instant Messaging and Unified Messaging solutions
  • Backup software
  • Fax software
  • Data archiving solutions
  • Journaling solutions
  • Antivirus software
  • Gateway and Spam filtering solutions
  • Load Balancers
  • E-mail Encryption solutions
  • Custom business applications
  • Monitoring and reporting tools
  • Outlook Client Plugins
  • Server administration toolsets

Designing Exchange Server solutions is complex. Consider all the above points but always try to keep the design as simple as possible. Sizing Exchange Server involves calculating the memory, CPU, storage, and network requirements to deliver a robust Exchange Server solution for a given organization to meet the technical and business requirements that have been agreed beforehand. The sizing process also includes providing redundancy at the database, server, site, or regional level, and also includes providing redundancy for the server infrastructure.

Hardware sizing involves some complex calculations. To make this process easier Microsoft provides the Exchange Server Role Requirements Calculator tool to help Exchange Administrators and solution architects design Exchange Server solutions. This is an Excel-based tool that takes the information outlined as required above and then makes recommendations for server infrastructure to deliver the requirements. The worksheet is divided into seven sections as shown below:

  1. Environment Configuration
  2. Mailbox Configuration
  3. Backup Configuration
  4. Storage Configuration
  5. Processor Configuration
  6. Log Replication Configuration (Optional)
  7. Environment Customization (Optional)

Details of how to use this tool and how to interpret the results generated are given on the Exchange Server Role Requirement Calculator section of this site.

As stated before, designing Exchange Server solutions is complex. But if you follow the advice given here and gather an in-depth understanding of all the technical and business requirements for an organization, then use the Microsoft tools, you will get a robust design that you can implement with confidence.