Hybridconfiguration after migrating an IMAP Server

[Ornelam]

Hallo everyone. I have a customer that want to join the Microsoft 365 world. The actual infrastructure is this: Microsoft Active Directory in the functional level 2016, and an Local Linux Server than can communicate just over IMAP. The goal is to install Azure AD Connect, so the users do not have to have two different accounts (local and Cloud), and create a hybrid Deployment. I plan to install an Exchange Server 2016, and to use it for users and mailbox management. My doubts are:

Do i install the exchange first, run the HCW and than install the AAD connect, ore use a different sequence? Hase anyone any tipp for me?

[#2]

Hello @Ornelam

PLease have the AAD Connect installed first to have hybrid identities. 
After that I would not bother with an on-premises messaging server anymore but go for M365, probably E3 license, for each user. All your configuration happens in the Office portal and the clients Outlook can be directed to get the mails directly from Exchange online. Saved my a lot of work and trouble.

I hope that helps.

Cheers
Rolf
#MCT #LearnWithRolf #TheCloud42  

[#3]

Thank you. I want to migrate the existing mails, and to do that i should have all my users in the cloud, and i should give them an exchange licence. If i run ADconnect first, how can i be sure that than the exchange server that i want to install for management (i dont want to manage my user mail attributes with Powershell or ADSIEdit) will than know that the users have all their mail in Office 365? 

[#4]

@Rolf-42 I dont know and i havent find any document till now: can i build a hybrid Deployment after a migrate all those mailboxes and have them all in the Cloud?

[#5]

Hello @Ornelam

May this can help you:

https://docs.microsoft.com/en-us/exchange/mailbox-migration/migrating-imap-mailboxes/migrating-imap-...

And you do not need an Exchange server for the management. All is done in portal.office.com

I hope that helps

Cheers
Rolf
#MCT #LearnWithRolf #TheCloud42