Migrating to Office 365: Important Things to Consider

Migrating to Office 365: Important Things to Consider

February 27

Guy Baroan is founder and President of Baroan Technologies.

Microsoft’s new Office 365 offering is a game changer, especially for the SMB market. Anyone who has a Microsoft Small Business Server with Exchange included, or decided previously to host Exchange internally, will definitely want to consider moving to Office 365 for several compelling reasons.


For us, cost is at the top of the list of reasons to move. When we do the math for our clients, there is no situation where it makes sense for them to bring Exchange in-house. Not one.


We’ve found having Microsoft host the service at their data centers is great if interruptions occur locally. Anyone that was using Office 365 when Hurricane Sandy hit the east coast in 2012 was able to continue working, while everyone else was dealing with power outages for weeks. And even if Office 365 is not safe from human error or data sync issues, you always have the option of an affordable and reliable cloud backup.


That said, there are many things you’ll have to take into account if you’re considering a migration. Let’s take a look at some of the common issues we’ve encountered in our migrations. For a full listing of the requirements please go to the Microsoft Office 365 site.

Workstation and User Considerations

  • Your clients need to use at least Windows 7 or Mac OS X 10.5 with all the latest service packs and patches. Note that Windows XP with SP3 and Vista SP2 are supported for now, but won’t be after January 1, 2014.
  • If they will be using Outlook locally, they’ll need version 2007 or newer for Windows (or Office 2011 on Mac), again with all the latest MS Office service packs and patches.
  • They will also need the latest version of IE, Firefox, Chrome, etc., especially if they’re going to use the Outlook Web App.
  • If your clients have any .PST files, you’ll need to find out whether or not they want to move them to Office 365. There’s is a limit of 25GB per mailbox as part of the service, so if you’ll need more than that, you’ll have to figure something out.
  • You’ll also want to consider mobile devices. Are they approved devices (iPhone, Blackberry, DROID or Windows Mobile) with the latest software version? If not, will they sync with Active Sync? Your clients may need to wipe their devices to resynchronize with the new service, so make sure they’re prepared for that. You’ll also want to know if administrators should have access to these devices when the migration is taking place.

Server Considerations

  • Your clients will need to be running Windows Server 2008 with all the latest service packs and patches.
  • Find out if your clients have in-house applications that MUST have an internal mail server or access to relay? If so, make sure to go over the Office 365 limits with them.
  • They must be running Exchange 2003.
  • Unfortunately, if your clients are using public folders, they’re out of luck. Public folders are not currently available. Microsoft may make them available in the future, but for now, your only option is to purchase another mailbox that can work as a public folder.

Active Directory and Single Sign-on Considerations

  • If your clients need a single sign-on experience, their active directory will tie into the Office 365 setup and allow the administrators to change the password in active directory, which will then change it on the Office 365 servers. The “gotcha” here is that to accomplish this, the client will have to have at least five additional servers available for this to work (two ADFS 2.0 proxy servers and ADFS 2.0 servers (two minimum for redundancy) and a DirSync server).
  • High availability is also an issue for single sign-on clients. Since outside clients have to authenticate with the active directory servers, they will have to first verify their credentials with the active directory servers at the office. This means that if the office is down, the outside users will have no way to get their emails from Office 365. Clients will need to weigh the pros and cons if they want to achieve a high level of availability.

Connection Considerations

  • Migration will take longer for clients who lack a fast Internet connection. The files first have to be uploaded to the cloud, then brought back down to sync with the Outlook clients. Depending on the connection, it could take a few days or longer for the migration to be completed.
  • Your clients may need the extra bandwidth to get the most out of Office 365 so if they don’t have multiple connections they should consider it.
  • In the same vein, if their firewall doesn’t support multiple internet connections, they should consider building one that will. Most newer firewalls will support multiple connections.
  • Be sure your clients know that with Office 365, internet access becomes much more critical as without it, they can’t see their email. They can use a mobile device for the email, but their local client or Outlook Web App will need Internet service to have access. We normally recommend that our clients have two different services: one from a phone provider and one from a cable provider so their networks are not shared. Also, the chance that the two will be down at the same time is very small.

DNS Considerations

  • Your clients will need to be able to modify their DNS records, so if don’t have immediate access to them, they’ll need to find out who does.
  • If the DNS host does not allow multiple records to be added for the domain, you may want to transfer to one that does.
  • You’ll want to know the time-to-live (TTL) setting. Once you are ready to move the service over, make sure you know how long will it take to propagate through the internet.

Added Benefit

That was a pretty big list. There’s certainly a lot of work to be done prior to migration but once email is migrated, there’s not much else you’ll need to do. Also, keep in mind that while some of these tasks seem like a lot of work, none of them are out of the ordinary. In fact, if the network was kept up to standards as required for security and functionality, there would really be very little to get done. Unfortunately, there are people that are too busy to keep up with the maintenance work. Going through this process is actually good for the client as it will bring them up to the security and functionality standard they should be at.

Photo Credit: Microsoft Sweden via Compfight cc