Office 365 Migration Must know..
Migrating to Office 365 is becoming increasingly popular among small to large Companies. The upside of moving from an on-premises environment to one hosted online by Microsoft offers a lot of benefits.
Whether you are thinking of going hybrid or taking the full Office 365 experience, you will walk into 1 or 2 hiccups a long the way.
If you're looking for solid, step-by-step help in deploying Office 365, check out Exchange Server Deployment Assistant. This free tool from Microsoft will allow you to choose a scenario that makes sense for your organization's needs. Answer a few simple questions, and Exchange Server Deployment Assistant gives you all the steps necessary to make your migration work, including how to set up single sign-on, AD synchronization, certificate configuration, and more.
Unless it's a greenfield deployment of Exchange Online through Office 365, you're looking at a migration. In that case, with an existing Exchange environment, you're typically taking a hybrid approach, mixing on-premises Exchange mail use with Office 365 use.
How long to remain in hybrid mode depends on your organizational goals. You may maintain a hybrid environment for an extended (or even indefinite) period because you don't wish to move all mailboxes to the cloud, allowing greater on-premises control for certain mailboxes. Or you may have sites that experience latency issues connecting to cloud-based mailboxes, in which case you should consider maintaining on-premises Exchange servers for those locations.
Hybrid deployments can be configured with Exchange 2007 through 2013 environments. However, with Exchange 2007/2010 environments there must be at least one Exchange 2013 Client Access and Mailbox server in place to run the Hybrid Configuration wizard. It's recommended you run the two roles on the same server. If your organization doesn't have Exchange 2013 (CU1 or higher) in place, you'll have to update your environment before going hybrid.
Message retrieval is a common pain point for admins. With Office 365, that pain can be unbearable, as Office 365 doesn't perform message retrieval beyond the deleted item retention limit, which is 14 days by default.
There's an easy solution: Alter your deleted item retention limit. Of course, it's a little trickier with Office 365. As opposed to on-premises Exchange, where you can touch the servers directly and alter the retention time, Office 365 requires a remote PowerShell connection to make the change. Here's the bad news: The max retention limit is 30 days. There are two ways around this gotcha. You can put mailboxes on Litigation Hold, in which case you may look to add the archive add-on piece for limitless hold, or you can implement an archive solution that works with Office 365 so that messages are retained and easily recovered.
Be sure to thoroughly vet your plan's offerings and research the "purchase services" option through your Office 365 dashboard to determine whether any of the paid services will be required for your organizational needs.