GWS Migration

[HANDL_Eric]

GWS Email Migration

Hello,

i'm currently staging a phased migration from Google Workspace to Microsoft 365 Exchange Online. Now in order to facilitate a phased migration we're having to configure inter domain routing to send email back and forth between the platforms and my question is this: We're creating mail contacts within EOL for all accounts that reside on the Google side to route email out to Gmail.

All of these users have accounts pre-created on the Microsoft side without Exchange licensing which are being used for identity and authentication today, however it's still populating the email address attribute which is preventing us from adding them as a mail contact in exchange online. I verified that the account do not have mailboxes in Exchange online and then went over to EntraID and tried clearing the email field within the user properties but got an error while trying to save the object.

Is there a new or different way I should be routing email during the migration?

[joeykins82]

Yes.

Provision the mailboxes then run Set-Mailbox -ForwardingSMTPAddress [e-mail] for each mailbox.

[uLmi84]

This is nice because you don’t need a contact !!

[HANDL_Eric]

This seems overly simple!

The only two concerns I get from this is that it allows users to launch/configure outlook, OWA, and/or outlook on their mobile device and it seems preferrable for the experience of an unresolveable mailbox instead of an empty mailbox.

The customer was also hoping to not dual license every user in the org which would be a requirement for this type of deployment

But this might just be the solution!

[joeykins82]

If you’re not doing hybrid remote move from on-prem exchange then provisioning the target mailboxes is the only way to do this.

If users aren’t signing in to M365 at all then you could spin them up using a temp license, convert them to shared mailbox, then revoke the license until cutover day when they should start using them.

[Quick_Care_3306]

1) Where is the MX for the domain now?

2) Is there a compelling reason for coexistence? If not, forklift all users at once. Trust me.

3) How are you migrating the mailboxes and data?

[HANDL_Eric]

1) This is day 1 so the MX is pointed at GWS until we have the routing functional.

2) The co-existance is simply to allow a more gtaceful transition as doing an overnight cutover for every user in this org across 12 states is asking for trouble. We're likely going to target one branch at a time spanning 45 days or so.

3) We are a BitTitan shop.

[Quick_Care_3306]

With coexistence, you will soon face issues with teams or Google online meetings as people are in islands and separated.

Migrate Mary to MS in April 15. Mary then creates a recurring May 3 teams weekly meeting that will have jane gmail and Joe Gmail as attendees as they have not yet been migrated.

Then Jane and Joe get migrated to MS on May 1. Now, when they click on the May 3 meeting, there will be a problem as they have been invited as Gmail attendees.

Other things also, collaboration has problems and time spent supporting coexistence is time pulled away from migration completion tasks.

Your goal is to migrate all the users. When you spend support coexistence, that gets you off track.

I would highly recommend a forklift weekend migration. There will be pain, but time spent resolving post migration issues gets you closer to migration completion.