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I'm going through the deployment assistant I'm just not sure it's going to advise thoroughly enough on handling duplicate usernames
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I'm going through the deployment assistant I'm just not sure it's going to advise thoroughly enough on handling duplicate usernames

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I am looking to get going on setting up an Exchange 2010 hybrid for my existing on-premise Exchange 2010 server.<br />
From what I understand, the first step in this process is to setup a new server for Active Directory synchronization with O365, is that correct? Should it be its own server or should I install that on the Exchange 2010 server? <br />
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As for the AD sync step, should I configure everyone's AD account UserPrincipalName to match their E-mail address? The reason I ask is because in our forest, there are two domains and potentially duplicate usernames/samaccountnames.<wbr /> <br />
So my understanding about the AD sync is that it might be better to ensure everyone's UPN is unique before starting the sync, and ensuring everyone can login to Exchange Online with their UPN federated domain instead of local.domain\username.
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I am looking to get going on setting up an Exchange 2010 hybrid for my existing on-premise Exchange 2010 server.
From what I understand, the first step in this process is to setup a new server for Active Directory synchronization with O365, is that correct? Should it be its own server or should I install that on the Exchange 2010 server? 

As for the AD sync step, should I configure everyone's AD account UserPrincipalName to match their E-mail address? The reason I ask is because in our forest, there are two domains and potentially duplicate usernames/samaccountnames. 
So my understanding about the AD sync is that it might be better to ensure everyone's UPN is unique before starting the sync, and ensuring everyone can login to Exchange Online with their UPN federated domain instead of local.domain\username.

Set up AD sync for Exchange 2010 hybrid - UserPrincipalName match e-mail?

Office 365 is a group of software plus services subscriptions that provides productivity software and related services to its subscribers. Office 365 allows the use of Microsoft Office apps on Windows and OS X, provides storage space on Microsoft's cloud storage service OneDrive, and grants 60 Skype minutes per month. Office 365 includes e-mail and social networking services through hosted versions of Exchange Server, Skype for Business Server, SharePoint and Office Online, integration with Yammer, as well as access to the Office software. All of Office 365's components can be managed and configured through an online portal; users can be added manually, imported from a CSV file, or Office 365 can be set up for single sign-on with a local Active Directory using Active Directory Federation Services.

Microsoft 365

Exchange is the server side of a collaborative application product that is part of the Microsoft Server infrastructure. Exchange's major features include email, calendaring, contacts and tasks, support for mobile and web-based access to information, and support for data storage.