NOTE: This process is for Hybrid On-Prem Setup
ON PREM EXCHANGE (WWCSV05)
1. Open Exchange Management Console (EMC) or Exchange Admin Centre (EAC)
For Exchange 2010/2013/2016/2019, use the Exchange Admin Centre (EAC) or Exchange Management Shell (EMS).
2. Locate the Mailbox
In EAC: Go to Recipients > Mailboxes, then select the user.
In EMC: Navigate to Recipient Configuration > Mailbox, then select the user.
3. Add the Alias
In the user’s properties, go to the Email Addresses tab.
Click Add (or the + icon).
Enter the new alias in the format:
alias@yourdomain.com
Ensure the primary SMTP address (the one with uppercase SMTP:) remains unchanged unless you want to change the default.
4. Apply and Save
Click OK or Save to apply the changes.
ON PREM ACTIVE DIRECTORY
Open ADUC → Find the user → Right-click → Properties.
Go to the Attribute Editor tab.
Edit the proxyAddresses attribute.
Add the alias as: smtp:alias@yourdomain.com (lowercase smtp: for alias, uppercase SMTP: for primary).
As the existing email will still be PRIMARY e.g. SMTP prefix
Add the existing email as: smtp:primary@yourdomain.com (lowercase smtp: for alias)
Remove the existing PRIMARY as: SMTP:primary@yourdomain.com (uppercase SMTP: for primary)
This should now have the new alias you created as the primary email. This will not affect any M365 Licencing