Office 365

Migrating to Office 365 requires planning and a pretty good knowledge of the environment you are going to migrate to. This will help you decide on the type of migration you need, for example, cut-over versus staged or hybrid migration. To help with this, you can use the Exchange Server Deployment Assistant at https://technet.microsoft.com/en-us/office/dn756393.aspx.

The aforementioned migration choices can be explained as follows:

• Cut-over: This is a one shot and you're done technique regarding moving all your data to Office 365. I would suggest you use the Assistant because there are limits as to how many mailboxes can be moved.
• Staged: This is a batch version of cut-over, where you move all your data in stages. This is a more managed approach to migrating.
• Hybrid: This option extends an on-premise server, and can be a permanent state or temporary. This option requires Azure AD Connect sync with an on-premise AD.

You will want to use multi-factor authentication, DLP anti-spam, encryption, and rights management, especially in the healthcare or financial arena. Migrations do not handle server-side public folders, archive data, or emails larger than 25 MB, nor client-side PST or local settings. This can make things tricky, especially in hybrid scenarios.

Looking at the solutions such as Dynamics and SharePoint, it is important to know that on-premise is most likely a version behind the cloud version and that most on-premise solutions work in Azure, but you must remember to test them.