Office 365 Exchange Online was a hot topic at IT/Dev Connections this year. The relevance of this has to do with the fact that many organizations are considering cloud based models for their future email deployments. This can be for many reasons of which can be cost savings, the benefit of not having to maintain onsite infrastructure, and the fact that Microsoft will do all of your Exchange related upgrades since they maintain the backend components for you. This article will cover some of the primary considerations that came from Office 365 sessions at IT/Dev Connections this week. Enjoy!


If you organization has made the decision to move to Office 365, it will be important to determine what type of migration you will be doing before getting started. Additionally, what are some of the considerations for how to figure out what type of migration you will need to engage in?


  • Cutover migrations are quick and typically would be done over a weekend. When determining if this is the right solution for your organization consider the fact that it is suitable for smaller organizations with fewer than 1000 mailboxes, and applies to on-premises environments running Exchange 2003 or later. This model doesn’t require DirSync and users do not need to be created in advance.


  • Staged migrations are best suited for larger organizations over 1000 users with mailboxes being migrated in batches up to 1000 per batch. Works only with Exchange 2003/2007 on-premises deployment only. Users will be provisioned with DirSync tool.


  • IMAP migrations to Office 365 is migration method used when your organization is using a non-Microsoft product for email. Examples of product might be Lotus Notes or GroupWise. Use of PowerShell to facilitate your migration is possible, but your organization will get their best migration results if you look at 3rd party migration options.


  • Hybrid migrations are useful if your organization is looking to move to the cloud, but needs to maintain a certain level of coexistence with an on-premises installation of Exchange 2010/2013. Some of the concerns with the option revolve primarily around the fact that Microsoft currently hasn’t created a set of hard and fast best practices for these types of deployments.


This only scratches the surface, but this is only the beginning of the thoughtful planning required to engage in a successful deployment. That being said, one of the sessions this week also provided a great set of questions to ask yourself before beginning a migration.


Here they are:

  • What are you migrating from and to? Understanding your current build helps provided better insight to migration options that can be used for your organization.
  • Do I have any other system integrations with my current onsite mail deployment? 3rd party archiving, fax, BES and Mobile Device Management to name a few.
  • What data are you migrating? Mailboxes, Public Folders, Contacts, pst files, etc.
  • Who is doing the work? Will Microsoft assist, a contractor, will I do the work myself, or will my users assist with certain aspects of the migration (ex. pst import)?
  • What tools will you use? Microsoft native or 3rd party
  • How long will it take? Always a challenge to determine, but with proper planning this can be figured out.


Finally, don’t forget your users and how they will be impacted by an Office 365 migration! Will their rules move correctly, or do they have some obscure setting that will not be migrated and needs to be reapplied after the move? Talking to your users and understanding how they use email today will only lead to a more successful migration to Office 365 Exchange Online.


So the best part is that all of these thoughts are only the beginning, but will only lead to a well thought out plan and design for your journey to moving your corporate email to the cloud.