Migrating from Microsoft Exchange to Microsoft 365 can seem daunting. Not all migrations are equal, so the approach shouldn’t be either. What methodology will work best for your unique business? How long will it take? Will you need a migration tool? What prep work is involved?

The list of questions goes on and on, so let’s take a step back and start with some basics.

What Is the Difference Between “Microsoft 365” and “Office 365”?

Initially, Office 365 referred specifically to the cloud-based business apps such as Office, Sharepoint, OneDrive, and was part of Microsoft 365, which also included Windows 10 and the Enterprise Mobility Suite of security and management apps.  

However, as of April 21st 2020, Microsoft officially renamed Office 365 to Microsoft 365 with varying subscription levels to allow businesses to choose a package that has apps and cloud services that specifically fit their needs. (Learn more about Microsoft licensing options here.)

Why Migrate From On-Premises Microsoft Exchange to Cloud-Based Microsoft 365?

Moving comes with a host of benefits:

• Always current software
  Not having to worry about upgrades. No down-time for users, no overtime for tech staff, and you can rest easy knowing security is always up-to-date.

• True flexibility to scale up
  Subscription-based licensing with a self-service portal puts the control in your hands to add licenses, seats, or functionality.

• Location, location, location…
  Get to everything, from anywhere, at any time. 2020 clearly taught us the importance of accessibility from any/all locations, and that flexibility is now becoming a significant factor in attracting new, highly-qualified talent. In a recent article by CPA Practice Advisor, “Nearly 9 in 10 workers considering a job change (87%) are interested in hybrid or fully remote positions.”

• Goodbye capital expenditures…
  Gone are the dreaded days of presenting a budget to management with exorbitant up-front costs for hardware, server, and individual client licensing. (And salaries to keep it all running.) A month-to-month subscription that covers it all means your technology costs are now operating expenses.

• Did we mention no more upgrades ... ?

How Do You Migrate From On-Premises Exchange Hosting to Microsoft 365?

What does it take to actually make it happen? Let’s take a high-level look at a few of Microsoft’s recommended approaches:

CUTOVER MIGRATION

With a cutover migration, everything is moved over at once, or over the course of a few days.  Mailboxes, calendars, contacts, and distribution groups are all migrated.  

Recommended when:

• Organization has fewer than 2,000 mailboxes. (However, for performance reasons, Microsoft’s recommended number is 150)
• Current on-premises setup is Microsoft Exchange Server 2003 or later

Overview of steps for a cutover migration:

STAGED MIGRATION

With a staged migration, mailboxes are moved over in batches over the course of a few weeks or longer depending on the size of the organization.

Recommended when:

• Organization has more than 2,000 mailboxes
• Current on-premises setup is Microsoft Exchange Server 2003 or Microsoft Exchange Server 2007 (which are both currently out of support)

Overview of steps for a staged migration:

HYBRID MIGRATION

There are many definitions of hybrid migration out there, and in some cases it is more aptly termed “hybrid deployment” as the end result is an ongoing environment split between on-premises and cloud. For the purposes of this discussion, we’ll highlight Microsoft’s three hybrid migration types.

Full Hybrid or “Exchange Hybrid Deployment”

• Recommended for large organizations with several thousands of employees, or organizations who will not be able to move all employees  
• Existing mailboxes are moved instead of new mailbox creation/import of user information
• AD (Active Directory) is synchronized with Microsoft 365
• Mail routing uses a shared domain name for both on-premises and Exchange online mailboxes
• Allows for calendar and free/busy sharing, and enhanced mail flow options
• Provides the ability to move mailboxes from on-premises server to Exchange Online, and back if needed
• Can remain a hybrid deployment longer-term or be used to manage a complete migration over a long period of time

Licensing Tip - Implement A Retention Policy

Most Microsoft 365 licensing comes with Exchange Online Plan 1, which is a 50GB mailbox. If you are migrating users with more than 50GB of files, you will need to add Exchange Online Plan 2 that covers 100GB. However, it's worth noting that Outlook only supports up to 50GB in cached OST email. This means it will really slow down the user experience over 50GB. A good fix to avoid latency is putting in a retention policy that requires employees keep email storage below 50GB.

Minimal Hybrid or “Minimal Hybrid Configuration”

• Recommended for medium organizations with a few hundred to a few thousand employees targeting a complete migration in a few months
• AD (Active Directory) is synchronized with Microsoft 365
• Ideal for companies who want to move all their mailboxes to Exchange Online over the course of a couple of months, with directory synchronization in place during the process
• Does not allow for calendar and free/busy sharing across environments or enhanced mail flow  

Express Hybrid or “Express Hybrid Migration”

• Recommended for small organizations who want a complete migration, but over a few weeks time instead of a one time cutover
• Some of the benefits of an express migration vs. a cutover include:
  • No downtime for users
  • Usernames and passwords will sync from on-premises
  • Outlook profiles do not need to be recreated

How Long Does a Migration to Microsoft 365 Generally Take?

Current environment, migration method, and volume of data are just a few pieces of the puzzle. The key factor in determining the time needed to successfully complete the move from hosting your own exchange servers to cloud-based freedom is the number of employees. Below is Microsoft’s suggested guidance around timelines but keep in mind this is specific to the actual migration itself.  Taking into account time for planning, preparation, etc. the whole process can take about 2-4 weeks.

Where Do We Start?

We all know prepwork is the key to successfully completing any IT task, but let’s be real, you already have a full-time job and a migration this critical is a pretty demanding ask. That’s where partnering with an IT services company with extensive experience with migrations can be a life-saver. After all, it’s not just about running the actual migration. There are many crucial steps that must be completed before the actual migration process such as:

• analyzing volume of data, number of users, uptime requirements, etc. to determine the best methodology for your unique business
• assessing the health of your current environment and performing any necessary patching prior to the migration process
• ensuring the correct identity model is in place, adding custom domains to the Office 365 tenant, and a myriad of other prerequisites
• addressing things like legacy archiving, mobile device connectivity routing, internet publishing, and many other “oh, we didn’t think of that” gotchas that companies can face in this process

It’s a lot to think about, and in some cases such as heavily-regulated industries, a complete migration may not be the most optimal solution. If you need assistance in determining overall feasibility, analyzing the best methodology for your unique business, or actually making it happen, Opkalla can help.  We offer a deep bench of engineers and expertise to move your organization to Microsoft 365 in both a timely and cost-effective way. Contact us today to set up a call (at no cost).