Forum Discussion
Can Exchange server and office 365 coexist?
1. Hybrid Deployment Advantages
Exchange Server and Office 365 can coexist, which is accomplished through Hybrid Deployment.
Hybrid deployment allows seamless integration of local Exchange Server with Office 365, allowing users to share mail, calendars and contacts between the two.
Seamless Migration: Users can be gradually migrated from local Exchange to Office 365.
Unified Management: Manage mailboxes locally and in the cloud through Exchange Admin Center.
Shared features: such as global address lists, busy and idle messages, and mail streams.
2. Requirements:
Supported Exchange versions: exchange Server 2010 SP3, 2013, 2016, or 2019.
Hybrid Configuration Wizard: simplify configuration using the Hybrid Configuration Wizard provided by Microsoft.
Network and certificates: ensure that the network connection between the local server and Office 365 is working properly and that a valid SSL certificate is configured.
3. Mail flow configuration:
In a hybrid deployment, mail flow can be routed through the local Exchange Server or directly through Office 365.
The send connector and receive connector need to be configured to ensure that mail is delivered properly.
4. authentication and synchronization:
Synchronize local Active Directory with Office 365 using Azure AD Connect.
Supports password synchronization, pass-through authentication, or federated authentication
Accually i wondered, do I need an exchange hybrid if I just use a different e-mail address for the same users. In that case they would have 2 mail accounts, one on each exchange, but that's ok in my use case.
Hybrid configuration is just a set of configurations that allows you to use the same email suffix (ie the "@currentdomain" portion of the email address in your example) in two different locations (on-premises and in the cloud). It's the email suffix that tells the world where your messages need to go (via the MX record in DNS). The email prefix (ie the "newmailaddress" portion in your example) is irrelevant for mail routing, but important in Exchange as Exchange won't accept messages for email addresses that don't exist (unless the domain is not authoritative in Exchange). You could set up a lot of the configurations manually, but it's really not worth it.
If your MX record points to on-premises Exchange for your "currentdomain" you need to somehow configure Exchange to accept the message and then forward it to Exchange online where the mailbox resides. There are multiple different ways to do this, but using the hybrid configuration wizard is the best and easiest.