Office 365 has a lot of fantastic features, capabilities, and functionality that will help your company stay up to the needs of today’s industry. We will look at some essential components of migrating to the Office 365 SaaS environment in this overview of performing an Office 365 migration.

Migration from on-premises to the cloud, on the other hand, is not a simple operation. There are numerous considerations of shifting to the public cloud that must be taken into account. This involves weighing the pros and cons of moving to the cloud. Is it appropriate for your company? What about the technical implications of a migration like this? There is a lot to think about.

Planning Decisions for Migration

Evaluating Costs

These considerations will have an impact on your decision to switch to Office 365. If you are considering it, this will be a useful module for you. If you have already decided that, your organization will migrate to Office 365, or if your customer has already made that decision and has hired you to complete the project, you should still go over these factors to ensure that your migration decision is valid and appropriate for your situation.

Although this is true in most circumstances, some people have discovered that cloud infrastructure is more expensive than on-premises infrastructure. It is crucial to realize that cloud computing shifts spending from capital to operational expense.

One benefit of this adjustment is that it will almost surely make spending more bearable. The cost of new physical servers, network equipment, and data center infrastructure to support backend systems might be significant. The cloud, on the other hand, operates on a simple “pay for what you use” approach, in which you are only paid for the resources you utilize.

Office 365 Licensing

This comes down to “per-user” licensing with Office 365, where you pay for an Office 365 license for each user who uses Office 365 resources. You may mix and match your Office 365 licensing, which is a great feature. You can mix licensing to accommodate the needs and features that your user base requires. For example, if some users only require an E3 license and only a few require E5, you can mix licensing to accommodate the needs and features that your user base requires.

The main aspect to remember is that migrating to the cloud should only be done after great study. A decision that is appropriate for one firm may not be appropriate for yours. Examine your requirements carefully, taking into account real-world business needs and the goals, you want to achieve with cloud migration.

Making assumptions about the ostensible benefits or cost savings can lead to migration with unexpected “gotChas” or consequences. From a corporate strategy and overall “big picture” standpoint, you want to give your migration due diligence.

Keeping up with Change

Before the period files the advent of cloud services, many organizations depended significantly on change control in their traditional IT models. Various stakeholders, project managers, change managers, and communications personnel subjected any modification to IT systems that potentially affect end users, whether it was routine maintenance or the introduction of a new product or feature, to a thorough review.

Then came the cloud, and businesses flocked to services like Office 365 for a variety of reasons. Migration projects got underway, and stakeholders were ecstatic about the cost savings, the easier administration, the improved security, or whatever other benefits they hoped to gain from using cloud services, until something in Office 365 changed one day, seemingly out of nowhere.

What kind of changes? It might be a new function, such as Microsoft Planner, that is being rolled out and made available to consumers. Some features are released in a preview form, which may contain problems or unfinished components, and subsequently become generally available, implying that they are ready for primetime use. A change in the behavior of an application, such as the introduction of Clutter in Exchange online, eventually evolved into Focused Inbox, which uses machine learning to distinguish important from less essential email in Outlook.

A change of a user interface, such as the OneDrive online interface over the years, and how operations, such as sharing a file, are carried out. Some of the modifications are hidden and only affect administrators, such as changes to the administrative portal interface or the relocation of some functionality from one portal to another.

Identity Models for Office 365

Choosing the correct identification model is maybe the most essential decision you will have to make straight away. How will your users be able to access your Office 365 environment?

Microsoft’s Active Directory Domain Services handles on-premises identity and authentication services for various enterprise environments. When migrating to Office 365, your ultimate goal is to provide a seamless experience for your end-users who may be authenticating on-premises while still accessing Office 365 services.

A successful Office 365 migration necessitates the selection of the appropriate identity model. This is critical since it affects many different parts of your Office 365 cloud implementation. This comprises the location of authentication, the amount of infrastructure-required on-premises for successful authentication, and the behavior and features of authentication based on the technique selected.

When moving to Office 365, Microsoft offers four distinct identity models. The mechanism for authenticating your end-users differs in each model. Each model has advantages and disadvantages that must be evaluated before deciding on the best model for your company.

The following are the four Office, 365 identity models:

  • Active Directory Federation Services (ADFS)
  • Pass-through Authentication
  • Cloud-only
  • Password Hash Synchronization

Let us take a closer look at each of these options and discuss the benefits and drawbacks of using each in your Office 365 authentication infrastructure.

Active Directory Federation Services (ADFS)

Active Directory Federation Services (ADFS) is becoming less popular because of Microsoft’s new options, such as pass-through authentication. Many setups simply do not require the extra capabilities and complexity that ADFS adds.

ADFS has many features and capabilities that provide you a lot of control and customization over how you authenticate. This includes the following:

  • Users can be filtered based on their client’s location.
  • Customization of the login page’s appearance and feel (custom branding)
  • Capabilities for single sign-on
  • Immediate security measures, such as account deactivation and logon limitations, are in place.
  • Multi-factor authentication via a third party

Using ADFS to authenticate your end-users has some drawbacks. These are some of them:

  • Your on-premises architecture is completely reliant on your authentication mechanism.
  • ADFS is complex to set up and even more difficult to troubleshoot if something goes wrong.

Pass-through Authentication

Pass-Through Authentication is a new solution from Microsoft for synchronizing passwords between on-premises and Office 365 online. When compared to password hash synchronization, this novel password synchronization approach offers more features.

It is a “happy medium” between password hash synchronization and Active Directory Federation Services in terms of functionality (ADFS). User accounts and passwords are synchronized between on-premises and Office 365 with pass-through authentication.

The authentication request is routed back down to the on-premises infrastructure when a user authenticates to Office 365. There are a number of benefits to using this method of password authentication. Active Directory Federation Services is very similar to these.

It enables you to:

  • You will have more control over your authentication system.
  • Instead of taking place on the cloud, the authentication procedure takes place on-premises.
  • Account modifications are immediately reflected (account disabled, logon restrictions, etc.)
  • When compared to ADFS, this is a simpler approach.

When employing the pass-through authentication technique, it is vital to remember that the availability of authentication is entirely up to you. To provide high availability, this usually entails putting up additional pass-through authentication agents.

Cloud Only

The cloud-only authentication method is the most straightforward to set up and requires the least amount of infrastructure. Because there is no synchronization between on-premises and the Office 365 cloud, this is the case. Your users’ access to Office 365 resources is authenticated in the cloud-using Azure AD. In this paradigm, there is no connectivity between your Azure AD environment and your on-premises Active Directory infrastructure. Because there are few moving elements, the process is simple to establish and manage.

Why wouldn’t you want to utilize a cloud-only authentication method? Your user accounts and passwords are not synchronized when you utilize cloud-only. This means that your end-users must remember their password for access both on-premises and in the Office 365 cloud. Due to the risk of login discrepancy, many organizations that now employ on-premises Active Directory Domain Services authentication may find that this is not the best way to authenticate users to Office 365.

Password Hash Synchronization

Many businesses discover that cloud-only authentication is insufficient to meet their needs. They must be able to utilize the same set of credentials to authenticate users whether they are on-premises or accessing cloud resources. Setting up synchronization between on-premises Active Directory environments and the Azure AD-backed Office 365 environment is essential in this situation.

Microsoft has provided several options for doing so. The first is the synchronization mechanism for password hashes. The password hash synchronization authentication mechanism is one of the oldest solutions for synchronizing on-premises user credentials that have been available for a while.

A Microsoft tool named Azure AD Connect is used to synchronize password hashes. Azure AD Connect is a software component that connects to both the on-premises Active Directory system and the Office 365 tenant environment. It is installed on-premises. The password hash is then synchronized between the on-premises Active Directory system and Office 365 environment.

It is easy to configure and requires very little in the on-premises infrastructure as it uses password hash synchronization. You can also utilize with Azure Multiple-factor authentication.

Some key Points of password hash synchronization are as follows:

Azure AD Connect synchronizes accounts based on a period unless manually configured. You must wait for each synchronization interval to run before the accounts are synced up unless you manually run the synchronization process.

Logon limitations are not synchronized when using a password hash.

Let us look at a newer type of password synchronization that addresses some of the issues that password hash synchronization has.

Evaluating the Type of Execution and Migration

After you have decided on the type of authentication model you will use and how your identities will be validated across on-premises and the cloud, you will need to figure out how you will carry out the migration. Users can transition to Office 365 using one of four different migration options.

These are as follows:

  • Cutover Migrations
  • Staged Migrations
  • Hybrid Migrations
  • IMAP Migrations

Cutover Migrations

When moving from an on-premises version of Exchange, such as Exchange 2003, 2007, 2010, 2013, or 2016, a cutover migration is supported. Cutover is supported for up to 2,000 people, when you walk through the actual cutover migration procedure, migrating that many users this way would be quite difficult, and even Microsoft recommends that you consider more like 150 users. All mailboxes, contacts, and distribution groups from an on-premises Exchange organization will be migrated during a cutover migration. Public folders and dynamic distribution groups will not be migrated during the cutover process. When you do a cutover migration, the migration procedure creates users and mailboxes in Office 365 for you. As a result, you will not be able to synchronize and manage on-premises items in Azure AD using directory synchronization.

The migration is started from Exchange Online and uses the same protocol as remote Outlook clients to connect to your Exchange Server on-premises. Initial synchronization is performed during the migration procedure. This first synchronization procedure will take as long as it takes, depending on the amount of information to migrate and the available network bandwidth to pull the data into Office 365. Email messages, contacts, and calendar entries are examples of mailbox content. Inbox rules, delegate calendar permissions, and email signatures are not included in the mailbox settings.

Staged Migrations

Only Exchange versions that do not support the hybrid migration can use a staged migration. Exchange 2003 and 2007 are the only versions that allow this. Because these are both end-of-life items, staged migrations are unlikely to be employed frequently. Because staged migrations are limited, if possible, use hybrid instead.

You will not be able to do a staged migration if you are operating Exchange 2010 or higher, so you will need to use the hybrid migration instead. You can build migration batches with the staged migration. The migration process configures mail forwarding to Exchange Online. You run a conversion script to convert mailbox users into mail-enabled users after a batch is finished.

If you want to go cloud-only, you can remove directory sync and exchange server once all migration batches are complete. However, keep in mind that the purpose of a staged migration is to fully migrate to the cloud rather than to create a permanent hybrid connection environment.

Hybrid Migrations

Versions of on-premises Exchange that allow hybrid connectivity support the hybrid migration. This applies to Exchange 2010 and later versions. It is worth noting that this can apply to mixed businesses with Exchange 2003 or 2007 servers and an Exchange 2010 server capable of establishing hybrid connectivity.

Microsoft even provides a free “hybrid-only” license for Exchange 2010, 2013, and 2016, which allows you to set up the hybrid connection for this purpose solely if your server does not host any mailboxes. The hybrid procedure does not have a minimum or the maximum number of users that can be transferred. Another important issue to keep in mind is that this hybrid license is not available for the 2019 Exchange.

When you choose the hybrid approach, you use Azure AD Connect to set up directory synchronization. It creates a real hybrid mail flow. A uniform GAL, cross-premises free/busy data and unified management are all included. The sole option allows users to remove their Office 365 mailboxes.

IMAP Migrations

IMAP migrations extract mailbox contents and migrate them to Exchange Online mailboxes using the IMAP protocol. Because IMAP is a widely used protocol, it can be used to migrate from non-Exchange systems to Office 365. IMAP migrations can be used to move from services such as Gmail, Yahoo Mail, and Outlook.

In that you synchronize the mail across and then manage the cutover of mail flow by altering MX records, IMAP migrations are logistically similar to cutover migrations. One significant distinction is that before you begin an IMAP transfer, you must manually create user accounts in Office 365 and build Exchange Online mailboxes for them. Unlike a cutover migration, the IMAP migration method does not automatically construct them for you. You will also need to know all of the individual account passwords for the mailboxes you are migrating from because an IMAP conversion normally implies you do not have admin access to the source email server. IMAP migrations are similarly restricted to individual mail items. Calendars, contacts, or any other type of mailbox content or mailbox settings information is simply not supported by the IMAP protocol. IMAP is a very basic protocol. There is a restriction of 500, 000 items per mailbox and 50, 000 total mailboxes, in addition to merely moving email content.

We know, at least, that there are IMAP migrations as an option, and perhaps you can examine this option if you are prepared to migrate into Office 365 and ask how your email will be removed from Gmail or Yahoo or your mailboxes hosted by ISP.

Third-Party Migration Tools

Migration tools from third parties are shown in the Office 365 email migrations image. They all offer various scenarios, and many firms can select and retrieve successful migration from one of them. There is, however, also a healthy ecosystem for the use of third-party instruments for Office 365 immigration and these are essentially designed to achieve two objectives, scenarios in which the indigenous methods of migration are not working, such as movements between the two separate Office 365 tenants and scenarios when the indigenous movement methods work.

Some of how third-party migration tools can improve this experience are by pre-syncing the oldest mailbox data into the cloud so that the actual migration process is faster as the information has been transferred before you begin to disturb users. Some programs offer scripts or agents to automate the development of Outlook profiles. Some offer additional capabilities for handling the migration of personal and PST files or by handling public folder data migration for you or by migrating users’ period files to OneDrive.

Third-party tools can improve project management capacity by automating communication with migrating end-users so that they always get the information they need to know exactly when they need to know and provide project managers and other stakeholders with a better understanding of migration processes. You can see that the usage of native migrations and provide a better migration experience can be substituted for tools by third parties, but they are naturally at an extra expense.

There are a number of excellent tools and services available from third parties that can help you with your migration effort. Some of them are what? Please check out the following third-party providers of incredibly amazing migration tools:

  • Sky Kick
  • Bit Titan
  • Code Two

Dealing with E-mail Archives and PST Files

E-mail archives via Exchange mailboxes and PST files, which contain old e-mail data, are now widely used in most companies operating Exchange Server. Let us first look at the archive of email. These can be found in:

  • Exchange mailboxes for archives
  • Archive of Journal
  • Systems for email archives of third parties

In hybrid setups, Microsoft Exchange native archiving technologies such as Exchange archive mailboxes can be moved directly to Exchange Online. You have the option of migrating the archive mailbox before or after the primary mailbox to which it is linked. When moving this data, keep in mind that Exchange Online archiving is an extra fee with Office 365’s basic plans.

If you have the space, putting the email in the archive boxes back into the primary mailbox provides an option to the increased expense of Exchange online archiving in Office 365. The data can then be transferred to Office 365.

In-Office 365, there is no option for a journaling mailbox. If you want to keep using this feature, you will need to use an on-premises Exchange server or a third-party journaling/archiving solution.

What about Outlook Express (PST) files? PST files can be an Exchange administrator’s worst nightmare. PST files are difficult to deal with, easily corrupted, and impossible to manage and even account for throughout an Exchange environment.

The PST collection tool from Microsoft is a free utility for Office 365 users. To have a clear way to import PST file data into your Office 365 environment, utilize this in conjunction with the Office 365 Import Service. Additionally, third-party software exists that enables the scanning and import of PST files. Third-party programs for handling PST file imports into Office 365, in general, will have more sophisticated feature sets.


Businesses today trying to stay competitive across a variety of industries can benefit from migrating to Office 365, which offers many amazing features and capabilities. Hosting important business features like email in Office 365 has many advantages. This includes moving away from significant capital expenditures and toward a more manageable operational cost. It also enables access to the most recent versions of Exchange on the cloud at all times.

Migrating core services can also relieve IT employees of many of the boring daily operational responsibilities associated with administering Exchange and other on-premises services, allowing them to focus on supporting applications that are more directly relevant to the business.

However, you must carefully analyze the reasons for migrating to the cloud and confirm that it is the best decision for your company. When considering a transfer to the Office 365 cloud, this is the first and most important step. Following the decision to migrate to Office 365, a number of measures must be performed to guarantee that the Office 365 services are successfully implemented.

These include determining the appropriate identity model for your company, the best migration approach, how to handle archive mailboxes and PST files, and how to best drive adoption when the conversion is complete. Your Office 365 migration plan will be more successful if you thoroughly evaluate, plan, and execute it.