How to Use SMTP Matching to Match On-Premises User Accounts to Office 365?

You can easily create a sync between on-premises Exchange Server and Exchange Online (Office 365) to synchronize users, groups, contacts, and other information so that you can simulate a single sign-on with one account and one password with the local setup and the online counterpart. In this context, you can use the Azure Active Directory Sync (AADS) when migrating the data and accounts from an on-premises Exchange Server to Exchange Online. You can transfer the authority from the Active Directory Domain Services (AD DS) to the local Active Directory. This can be used to have a synchronization between the local Active Directory and the Exchange Online so that the migration can be a smooth one with minimal impact to the users. This way the users would only need to remember one username, i.e., the email address and one password for their local and cloud account. Below, we will be discussing how to use SMTP matching to match on-premises user accounts to Office 365.

Process to Use SMTP Matching to Match On-Premises to Cloud

Let’s start with the SMTP matching process to match the SMTP address at the local setup with the Azure identity that has the same email address. This can then be used to migrate the data accordingly.

• Sign in to your Office 365 tenant with a global admin.
• Click on Admin and then click on Show All.
• Click on Exchange, under the Admin Centers.

• Under Recipients, click on Mailboxes.
• Double-click the user to grant authority.
• Click on Manage Email Types and note the primary SMTP address which is in caps and bold.

• From the local Active Directory server, open the Active Directory Users & Computers.
• Create a user same as the online counterpart and set the SMTP address of the user to match the online identity. It’s best to use either the E-mail field or the Attribute Editor in the Advanced Feature, depending on the user (if it is a new user or an existing one).

• In the Advanced Feature, click on View and then click on Advanced Features.
• Now re-open the user and click on the Attribute Editor tab.
• Scroll-down until you find the attribute Proxy Address and click Edit.

• Make sure that you edit the one with the SMTP in caps. Then, click OK.

• If you have an on-premises Exchange Server, you might need to edit the E-Mail Address Policy so that the user can be reflected with the desired email address to match the one in the Azure Identity.
• Now, in the Azure Active Directory Sync (AADS), you need to wait for the next scheduled delta synchronization or run this manually using the following command.

Start-ADSyncSyncCycle -PolicyType Delta

The synchronization process is now complete. The local user and Azure identity should match.

Limitations of SMTP Matching

There are some limitations of the SMTP matching process that might hinder the process at hand. These are:

• SMTP matching will work for users with an Exchange Online email address. For matching the SMTP with contacts and mail-enabled groups, you must make use of the proxy address and it must exist in the Exchange Online environment.
• It’s important that the SMTP address of the Exchange Online resources will not be changed during the synchronization since it is the only anchor with which the matching can occur between the on-premises server and the Azure identity.
• It’s important to run a cleanup process and ensure that there are no duplicate email addresses as this will hinder the synchronization process.
• You cannot just match and unmatch the users from the local servers and the cloud identity. When the match is primarily done, it creates a bond between the local user’s GUID and the online user’s GUID.

To Conclude

Sometimes, the process to match on-premises user accounts to Office 365 during a migration can be a little bit tricky. However, issues can arise due to several reasons and system limitations. If you encounter any issues or errors during the SMTP matching, it would hinder the migration process.

For smooth and quick migration process, you can use specialized EDB to PST converter applications, such as Stellar Converter for EDB. This application can help you migrate user mailboxes, user archives, shared mailboxes, disabled mailboxes, and public folders from EDB file to Office 365 (Microsoft 365) with ease and peace of mind. You can also directly export from an online or offline EDB file to a live Exchange Server. It offers features like automatic mailbox matching, parallel exports, priority exports, and continuation in case of interruption.