1. What is Exchange Online :
Unified communications is one technology trend that is seeing growth in nearly every business vertical. With an increased need for real-time communication and collaboration
in order to stay competitive in business, organizations are turning to services such as Microsoft Exchange to improve anywhere access to key information, calendaring, and corporate communication.
Microsoft Exchange Online is designed for organisations who want to benefit from cloud-based email without sacrificing the business-class capabilities that Exchange Server has always provided. Built on the same technology as Exchange Server 2010, Exchange Online
provides organisations with the latest capabilities including; built-in archiving, optional Conversation View, and MailTips, along with powerful web-based tools for managing online deployments. Microsoft handles the ongoing maintenance, patches and upgrades
of the Exchange infrastructure while providing IT administrators the control and flexibility they require.
2. Features in Exchange Online :
3. Transitionning steps :
hen migrating from Exchange-based environments, you can establish directory synchronization so that AD users, groups and contacts are replicated to Exchange Online from your on-premise Active Directory environment.
This will create a temporary unified GAL during the migration period. In addition, you will be able to share the same SMTP domain name between your on-premise messaging infrastructure and Exchange Online and thereby establish true e-mail coexistence.
Windows 2000, 2003 and 2008 Active Directories are supported by the Exchange Online migration tools.
Also, you do not necessarily need to migrate all your Exchange users, groups and contacts to Exchange Online, it is also supported to run in hybrid mode, where you migrate some of your users, groups and contacts
to Exchange Online and keep the rest on-premise. If your business has a large and complex messaging infrastructure it is often a good idea to keep some Exchange servers in the on premise environment, as you probably have line of business applications that
uses Exchange for relaying purposes, custom connectors to other systems etc.
Another thing worth mentioning is that you do not necessarily need to manage users, groups, and contacts that have been migrated to Exchange Online via the web-based Exchange Online services portal. Actually
if you set up directory synchronization from your on-premise environment to Exchange Online, you must manage these objects via the Active Directory Users and Computers and Exchange Management Console MMC snap-ins or the Exchange Management Shell. Replicated
objects cannot be managed via the Exchange Online services portal.
If you are establishing a greenfield, you can also create a brand new Exchange Online based messaging environment in which you manage Exchange objects via the Services portal.
Inbound e-mail from the Internet to Exchange users, groups and contacts hosted at Exchange Online is routed through Exchange Hosted Services. You can choose to have inbound mail point to your on-premising infrastructure
or directly to Exchange Hosted Services, which routes it on to the respective Exchange 2007 server at Exchange Online.
in one shot of less than 1,000 mailboxes from Exchange 2003, Exchange 2007 or Exchange 2010 :
Cutover Exchange Migration
is the easiest way to provision cloud-based Exchange Online mailboxes and then migrate mailbox data to the cloud from your on-premises Exchange server. This option migrates your organization’s distribution groups, external contacts, email messages as well
as other Exchange mailbox data such as calendar items, contacts and tasks. This allows you to migrate all of your mailboxes at once, such as over a weekend and is ideal for a small to medium sized organizations that desire less complexity and a short migration
timeframe. You also do not need to install and configure the Microsoft Online Services Directory Synchronization tool or DirSync in this instance; this option is ideal if you plan on identity management entirely in the cloud. Please note that this method should
not be used if you plan to maintain any mailboxes on-premises after the migration.
Migrating mailboxes from Exchange 2003 or Exchange 2007 and you have one of these cases:
- Maintain mailboxes in your on-premises organization
- Have more than 1,000 mailboxes to migrate
- Have requirements to pilot or stage migrations
- Do not require calendar free/busy sharing between cloud and on-premises users
In these cases, staged Exchange Migration
may be the best option for you. This option allows your organization to move some mailboxes to the cloud over time while maintaining the rest of your mailboxes in your on-premises environment so you can migrate your mailboxes in discrete batches. You get a
unified global address list for both your on-premises and cloud-based mailboxes but need to replicate user objects from your on-premises Active Directory directory service to your Office 365 environment to do so; this means you will need to install and configure
the Microsoft Online Services Directory Synchronization tool and keep on managing user attributes in your on-premises Active Directory. For more information, see
Plan for User Identity in a Staged Exchange Migration.
Migrating mailboxes from Exchange 2003, Exchange 2007, 2010 and you have one of these cases :
- You need to maintain mailboxes both in the cloud and in your on-premises organization indefinitely
- You need to migrate all mailboxes to the cloud but have a requirement to pilot or stage migrations
of mailboxes over an extended period of time
- Have a requirement to have the smoothest possible migration experience including free/busy calendar sharing between cloud and on-premises users, have a single Outlook Web
App URL for both on-premises and cloud users
- You want centralize control of mail flow so your on-premises organization can control mail flow for both the on-premises and cloud-based organizations?
In this case, a
Hybrid deployment is likely the best option for your organization.
This enables seamless calendaring between hosted and on-premises users and all email looks and feels internal to the company; recipients on email are resolved as internal, MailTips will work correctly and OOF messages to internal recipients will apply to both
on-premises and Exchange Online cloud-based user mailboxes. Human resources teams or your compliance officers can conduct multi-mailbox searches/discovery across both on-premises and Exchange Online mailboxes. You can even move mailboxes back to on-premises
if requirements or scenarios change and users’ Outlook profile is preserved so users do not need to resynchronize or create new .OST files.
In the hybrid scenario, an Exchange 2010 SP1 (or higher) server must be deployed on-premises which acts as a gateway to the cloud; larger organizations will
typically deploy two of these servers for redundancy. There is no need to upgrade mailboxes to Exchange 2010 prior to moving them to the cloud if you are currently running Exchange 2003 or Exchange 2007. You can migrate and manage on-prem and online users
from the same Exchange Management Console or using Remote PowerShell. Setting up a hybrid deployment has more steps to consider than the other options but provides the most flexibility, particularly if your organization intends to maintain mailboxes on-premises
and in the cloud for an extended period of time.
Note: Currently, you cannot migrate directly from Lotus Domino to Exchange Online. You must first migrate Lotus Domino to an on-premise Exchange environment using
the Microsoft Transporter Suite and then migrate from there to Exchange Online. Alternatively, you must migrate from Lotus Domino using a POP3 or IMAPv4 based migration approach. But Quest Software should be working on a solution that will make it possible
to migrate directly from Lotus Domino to Exchange Online.