Problem
When you reply to emails after completing migration with EdbMails Exchange / Office 365 migration, your email responses are sent with the domain name of your new server.
Resolution:
Now that the source and target domains are different, you need to change your domain from the source environment to the new one to route all mail flow to the new server. For more details on how you can add a new domain to Office 365 or Exchange on-premises, visit the Microsoft article.
If you change the domain between two Office 365 tenants, make sure to remove the domain from the source tenant before you add it to the target.
After you change the domain, create aliases for the migrated mailboxes that point to the new domain. Additionally, make this alias the primary email address if you plan to send and receive emails from this address.
You can create an alias from:
- Microsoft 365 Admin Center ( Applicable only for Office 365 Mailboxes)
- Exchange Admin Center (Applicable for both Exchange Online as well as Exchange Server 2013 and the latest versions)
Microsoft 365 Admin Center
- Log in to Microsoft 365 Admin Center
- Choose'Users' < 'Active users' from the left panel
- Select the new user that you have migrated and click 'Manage username and email' under 'Aliases'
- Type the initial portion of the email address on the 'Manage username and email page', then choose your migrated domain name from the drop-down and click 'Add'
- As an optional step, click '…' and select 'Change to primary email' to make this the default email address for Office 365 login as well as to send and receive emails.
- Click 'Save Changes'
Exchange Admin Center
- Select 'Recipients' < 'Mailboxes' under 'Exchange admin center'
- Double click on the user mailbox and click 'Manage email address types' under 'Email addresses'
- Click '+ Add email address type'
- Select the 'SMTP' under 'Email address type'
- Enter the new email address and click 'OK'
- As an optional step, back on the 'Manage email address types' window, click the 'Save' button.
Consider utilizing the PowerShell command that enables you to add aliases to multiple mailboxes at once if you have a higher number of migrated mailboxes. Visit this
Microsoft page for the procedure