Migrating email to Office 365 can be smooth, or it can be downright ugly - learn what your options are, and how to choose the best fit for your company!

1. Migrating to Office 365:
The Good, The Bad, & The Ugly

2. What are my
options?
The Good:
The Bad: IMAP
The Ugly: PST
Import

3. Cons:
- Migration can be user driven
- No central control / management
- PST files must be discovered
- Corrupted PST files need to be managed /
repaired
- Manual effort, not feasible for large migrations
The Ugly:
PST migration to Office 365
Pros:
- Migration can be user driven
- Users can migrate content on demand
- Migrates mail, calendar, contacts, and
tasks

4. PST Migration: PST Capture Tool
- Console needs to
be installed on
premise (can be a
workstation).
- Requires Outlook
2010 (64 bit).
- Agents need to be
installed on all
workstations to
discover PST files.
- Slow, prone to
errors.

5. Prepare
CSV file &
launch
Import
Service Job
Mark
migration
as
complete
Monitor
import
&
Remediate
as
necessary
Change
MX
record
Provision
users
+
mailboxes
in O365
(license
assigned)
Create new
Outlook
profiles
&
Inventory
PST files
Upload
PSTs into
Azure
storage
PST Migration: PST Import Service
- Requires the AZ Copy tool to
be installed (command line
tool).
- Need to know where all the
PST files are, or copy to a
central location.
- Upload is much faster than
PST Capture Tool.
- More automation: PST
upload is scripted, CSV file
launches a batch process to
import emails.
- Email can be imported into
main mailbox or archive
- Still need to deal with PST

6. Third Party Tools:
- Provide automation options.
- Can streamline the migration
or import process.
- Can be used to reconfigure
Outlook profiles &
disconnect PST files.
- Can be agentless.
- Provide a console for
migration management.
- Can be pricey, needs to be
evaluated against business
needs.

7. The Bad:
IMAP Migration to Office 365
Cons:
- Only migrates mail, no calendars, tasks, or
contacts
- Won’t migrate folders with a “/” in the name
- Won’t migrate email larger that 35MB
- More effort required to create the migration
batches
- Less controls and lacks good migration reporting
- SLOOW
Pros:
- Works with a large number of source systems
- Users can be migrated in batches
- Works with on premise or hosted email systems
- On premise migration tools are not required
- PowerShell can be used to help automate the
process

8. Delta
sync
every 24
hours
Mark
migration
as
complete
Change
MX
record
Gather
IMAP
credentials
and
prepare
CSV
Provision
users
+
mailboxes
in O365
(license
assigned)
Wizard:
Enter
server
settings
and upload
CSV
Initial
sync
Final
sync and
cleanup
IMAP Migration Flow
- Manually create
distribution
groups.
- Provision
mailboxes in
Office 365 prior
to migrating
email.
- Requires
administrative
access to all
mailboxes, or
each user’s

9. Third Party Tools: Use them!
- Better automation options.
- Better control over the process.
- More options for reporting and
remediation.
- Better support (usually).
- Greater flexibility and
migration options.
- Can be used to reconfigure
Outlook profiles
- Provide a console for migration
management.
- Almost always worth the cost!

10. The Good:
Exchange to Office 365
Cons:
- Requires more effort to set up and configure
Pros:
- Greatest amount of control and flexibility
- Allows for cutover or staged migrations
- Allows for hybrid coexistence and
management
- Enables additional identity scenarios

11. Simple Migrations: Cutover Exchange Migration
- Used to migrate all
users at once (Big
Bang).
- Migrates all mailbox
data.
- Works with Exchange
2003 or newer.
- No coexistence /
DirSync – cloud
identities only.
- New passwords
created for all users
- Doesn’t migrate
messages over
35MB.
- Outlook profile is

12. Simple Migrations: Staged Exchange Migration
- Migrate users in
batches over a
period of time.
- Cannot be used with
Exchange 2010 or
newer.
- Requires DirSync to
provision and
maintain identities.
- Doesn’t migrate
messages over
35MB.
- Outlook profile is
recreated.
- Requires mail
forwarding once

13. Delta
sync
every 24
hours
Mark
migration
as
complete
Change
MX
record
Configure
Hybrid
Pre-Reqs
Configure
Directory
Sync
(install
ADFS &
SSO if
required)
Run Hybrid
Config
Wizard
Initial
sync
Final
sync and
cleanup
Hybrid Deployment: Exchange Integration
- Manage users on-
premises and online.
- Enables cross-premises
calendaring, smooth
migration, and easy
off-boarding
- Unified Global Address
List (GAL)
- Free/busy and calendar
sharing between on
premise and Exchange
Online.
- Maintain access to on
premise Public Folders
- Control mail routing (on
premise or Exchange
Online)
- Requires DirSync

14. https://technet.microsoft.com/exdeploy201
Deployment Tools: Planning
The Exchange Server
Deployment Assistant helps
you plan your deployment and
migration end to end.
A great starting point, whether
you’re deploying / upgrading
Exchange on premise, or
migrating to Office 365.

15. Deployment Tools: Troubleshooting
The Remote Connectivity Analyzer includes a number of
tools to test configuration settings and to troubleshoot
issues.
Included on that site now is the Office 365 Support and
Recovery Assistant, which is geared more around
troubleshooting and resolving common Outlook problems.
https://testconnectivity.microsoft.com

16. Thanks for listening!
http://masterandcmdr.com
@Remy_Dahl
jdahl@masterandcmdr.com
Jeremy Dahl, Office 365 MVP