Introduction
When considering an Exchange Online to Exchange Online migration, This list is little older but though to post to use as reference :
By addressing these migration points systematically, organizations can ensure a smooth transition and seamless functionality during the Exchange Online to Exchange Online migration process.
Migration Tasks
To Do
- Upgrade Clients to Office Pro Plus (M365 Apps)
- Manual Mailbox Move Consideration.
- Evaluate & Report Junk E-mails.
- Change User/employee Provisioning Scripts to Make O365 Mailboxes
- Assign Licenses to Employees and Contractors.
- Shared Mailbox Migration approach.
- Plan for updating/moving Exchange Documentation
- Add all accecpted domains into O365.
- UM Enable CSV Script
- RBAC Roles in O365
- Create Self Service Button for end users to initiate their mailbox migration.
- Create a promotional email template for end users to enroll in migration activity.
- Configure Prod Ready UM Dial Plans and Policies
- Disable POP and IMAP for all Users
- Get list of shared mailboxes that have sent emails in past 3 months
- Get list of shared mailboxes with Forwarding enabled.
- Add DDL as members of DLs in O365
- Identify Users with Send As Permission
- Convert Shared Mailboxes from User Type to Shared Resource Type
- Remove the double authentication prompt for SSO while logging from external network
- Sync discovery mailbox to cloud, this isn’t possible.
- Verify and add O365 Proxy Email address for all users.
- Sync UsageLocation for India Users, India doesn’t allow UM hence go for alternatives.
- Sync All mail enabled users.
- Sync Voice Mailboxes OU to O365
- UM Policy Migration
- EXO license Assignment
- Block inbound e-mails from internet to @tenantdomain.onmicrosoft.com
- Write-Back to On-Prem AD
- Audit and Reduce Voicemail Boxes
Problems to Fix
- AD Pictures don’t sync to cloud.
- Legitimate emails being marked as SPAM
- Forwarding back to on-prem not working
- Conf rooms don’t appear on room list after migration to cloud
- Exchange Data in Puerto Rico
- OWA Redirection for on-prem owa url no longer works
- O365 Mailbox can’t open On-Premise Mailbox through OWA
- disable popup for autodiscover certificate Outlook
- Retention Policies Not Following Migration
- Dynamic DLs doesn’t include O365 Mailboxes
Research Tasks
- Test Riverbed WAN Acceleration with O365.
- Monitor Pending Messages Queue in Office 365 or enabled alerting.
- See use of Accepted Domains on-premise to be changed to Internal Relay
- How to migrate Online Archive back to Primary Inbox.
- Graph API
- How to synchronize Voice mail PIN.
- Test 2-factor capability for all Client Types.
- Test Mailbox Permissions in Cloud when Granted through DL or Security Group
Known Issues
- Lync integration of owa doesn’t work in Office 365.
- Calendar delegation does not work across onprem/cloud
- Activesync username must be changed to UPN
- You cannot edit DLs through Outlook once you move to cloud
- Android Clients Need to be deleted and recreated
- Unable to enable UM for single user
- Can’t give full access to an on-prem mailbox when user is in cloud
Thank you for reading and I will update the doc to more modern approach.