Office 365 migrations

[TheOriginalStinger]

Hey i'm new to an organisation in wich I have to merge an on prem exchange server 2013 running on win server 2012 with office 365. To make things complicated those on prem users already have an office 365 account and email adress. What's best practice to migrate there on prem exchange inbox and shared calendar? If possible.

[#2]

Hi @TheOriginalStinger,

If you have no data on those Office 365 accounts, remove them and implement Exchange Hybrid and then migrate.

Please read more here https://docs.microsoft.com/en-us/exchange/exchange-hybrid

Best Regards,

Nuno Árias Silva 

[#3]

Hey Nuno, unfortunatly they already use both accounts, so inbox is used in both on prem and exchange online.

[#4]

Hi @TheOriginalStinger,

Depending on your scenario, you will need to migrate the content using a third-party tool, then you can implement hybrid and use a scenario of soft match to join the user https://support.microsoft.com/en-us/help/2641663/use-smtp-matching-to-match-on-premises-user-account....

Best regards,

Nuno Árias Silva 

[#5]

@Nuno Silva hey the users also are in an other domain will that matter. I don't need their domain 2 e-mail adress. It has to merge with the e-mail adress they already have of the principal domain.

Thank you!