Objective:
We plan to migrate our office 365 from our current tennant (E3) to a new tennant (M) to drastically cut our annual costs for the same services, while retaining the mail and group memberships of all our users. This will involve installing an exchange server to download and upload mail from the old tennant to the new tennant.
Background:
We are a longtime O365 customer, and have been a customer since before the "Midsize business" plans existed. There is no "cookie cutter" migration path from E3 to M. Microsoft currently recommends deploying an MS exchange server and off-boarding the mailboxes from your E3 subscription and then On-boarding them to a new account under the M plan. As ridiculous as this is, this is indeed the path our company has decided to go. It isn't cool/fair that we're being shackled to the E plans (that are vastly more expensive) when we're a small/midsize business that has been a longtime customer of O365, while new customers of equal size to us can expect to save over $4000 annually. The services (when compared) offered are nearly identical.
After calling MS support several times for guidance for this issue, I am advised that we should contact a 'partner' and ask for their support in doing this migration. We did as requested and were provided a quote to the tune of approximately $15,000 to do this migration for us. Obviously this is unacceptable, and thus our business has decided to rely on my abilities to get it done. Again, involving an MS partner is not an option.
Environment:
1 MS AD domain:
- Original FQDN was @contoso.ca of this domain and UPNs were firstname.lastname@contoso.ca
- UPN has been changed to firstname.lastname@corp.com to allow for ADFS
- ADFS has been deployed and SSO works for all users with UPN firstname.lastname@corp.com
- An "On-Prem exchange server" does not yet exist
1 O365 Account where main tennant FQDN is @corp.com
- There are 5 registered domains
-contoso.ca
-corp.com
- contoso.legacy.ca
-deprecated/will be deleted
-deprecated/will be deleted
- There are 40 E3 licenses, all using a @corp.com UPN
- There are 5 E1 licenses (we acknowledge that these will be upgraded to an M following the migration) that use the UPN contoso.legacy.ca
- No accounts currently use contoso.ca for email
- O365 was upgraded to 'the latest version' sometime in summer 2013.
Migration Plan (High Level):
Setup a local windows server (trial license)
- Deploy an exchange 2013 server (trial license) on the aforementioned windows server http://technet.microsoft.com/en-us/evalcenter/hh973395.aspx
- Prepare and deploy Dirsync Deployment of Dirsync
- Add exchange to office 365 and begin replicating the mailboxes from the cloud to the exchange server. Wait for synchronization to complete.
- More information: http://technet.microsoft.com/en-us/library/hh534377(v=exchg.150).aspx
- http://help.outlook.com/en-us/140/ff633682.aspx
- Evaluate total time it took to sync data.
- Time it takes to download data to exchange should be relatively similar to time it takes to restore mail to the new service.
- Open a new office365 account under the M plan.
- Plan a 1 hour mail & contoso.ca domain login outage
- temporarily change all user UPN's to match the new tennant
- perform a dirsync to the new tennant
- disable dirsync after all accounts have been auto-created/provisioned
- re-establish UPN + mail access.
- Plan a date and time for the cut over.
- remove the exchange hybrid server from the old tennant.
- Point MX records directly to the exchange server.
- Cut office 365 service.
- After the 30 minutes ~ 1 hour 'mandatory' wait time imposed by MS to 'register' the domain with O365, add @corp.com to the new tennant
- fix all user UPN's in the cloud to match their real UPN's.
- This can be done with powershell.
- attach exchange hybrid server to new tennant
- Point MX records to the new tennant
- Migrate all data from the local exchange server to the cloud under the new plan.
Current progress (Lab):
I have created a sandbox (Lab with no internet access or connectivity to production) environment in VMware and cloned the following servers to it:
1x Domain Controller (DC) running windows server 2012 (named DC02)
1x DC running windows server 2008 R2 (named DC01)
1x windows server 2012 R2 - prepped with all the pre-requisites to install exchange 2013. (named EXC01)
Where I am stuck / Problem:
I have installed exchange on the server EXC01 in the lab environment using my account. I am a domain administrator in the contoso.ca domain, but my UPN is firstname.lastname@corp.com.
After the installation of exchange, I notice that my email address in Active Directory changed from @corp.com to @contoso.ca. By default, I do not see @corp.com to be an available email address to select as my email address, and changing it in AD does not resolve the problem.
In the exchange portal, I found "Mail flow ---> Accepted Domains", and believe I should add @corp.com to the accepted domain list. Questions:
1) Must I add corp.com and the other domains that exist in office 365 to the local exchange before I go through with the hybrid wizard?
2) If I must add them to exchange, I am provided with three choices:
- Authoritative Domain
- Internal Relay Domain
- External Relay Domain
Given that the domain is currently in office365 and is authoritative there, which of these applies?
3) Most documentation I have found has been about a one way migration from on-prem to the cloud. I have had a hard time finding a step by step guide for cloud to local (new server) and then back to cloud. Does anyone here have any good documentation for this process? Would love it if it took into consideration multiple UPN/email addresses.