Outlook Mac App - reply with the correct alias email in from field

To ensure that replies to emails sent to your aliases use the correct alias in the 'From' field in the Outlook Mac app, you may need to adjust your settings or configurations. However, the Outlook Mac app does not automatically set the 'From' address to the alias from which the email was received. Instead, it defaults to the primary email address.

Currently, there is no built-in feature in the Outlook Mac app that allows you to change this behavior directly within the reply draft. The workaround you mentioned—manually changing the 'From' address in a new window—is a common approach users have to take.

If you want to streamline this process, consider the following:

1. Use the Outlook Web App: Sometimes, the web version of Outlook may handle aliases differently and might allow you to reply with the correct alias more easily.
2. Check for Updates: Ensure your Outlook Mac app is updated to the latest version, as Microsoft may introduce new features or fixes that could address this issue in the future.
3. Feedback to Microsoft: Since this is a common request, providing feedback to Microsoft about this feature could help prioritize it in future updates.

Unfortunately, there are no specific settings within the Outlook Mac app to automatically set the 'From' address to the alias when replying to emails sent to that alias.

References:

• Add another email alias for a Microsoft 365 business subscription user

Hi CS,

Welcome to Microsoft Q&A Forum! 

Have a good day and I hope you're doing well! 

I totally understand how frustrating it is when you hit Reply and the From field keeps defaulting to the primary address, especially after you’ve already set up your aliases. Based on my research and testing, it’s very likely your tenant hasn’t enabled “Send from aliases”. You can try the steps below:

1. Turn on “Send from aliases” in the Exchange Admin Center 

• Sign in to the Exchange Admin Center with an administrator account. 
• Go to Settings (left navigation) > Mail flow. 
• Turn on “Turn on sending from aliases” (Send from aliases) and click Save. 

Note: It may take 15–60 minutes (sometimes longer) for the change to apply across the tenant. 

2. Send from an alias in Outlook for Mac (New Outlook) 

• In the message window, check Show From to display the From field. 
• Click the From dropdown and select Other email address. 
• Enter your alias email address and click OK. 
• Compose your message and click Send. 

3. Double-check in Outlook on the web (OWA) 

• Open Outlook on the web > Settings (gear icon). 
• Go to Mail > Compose and reply. 
• In From addresses (or Addresses to send from), add/select the alias you want to appear in the From field. 

• New Message > … > Show From > From > Other email address > enter the alias > OK, then test sending/replying again. 

Tips after enabling 

• Restart Outlook (or sign out and back in) after turning on Send from aliases. 
• Send a test email to your alias, then click Reply to confirm the From field uses the alias. 

Notes 

• Make sure the alias is correctly added to the user’s mailbox in Microsoft 365 Admin Center (Users > Active users > select user > Mail > Email aliases). 
• If the alias still doesn’t appear after you’ve waited, try OWA first (it often updates faster), then test again in Outlook. 

I hope this information is at least partially helpful. If you have any concerns or questions or if anything I wrote is unclear or I’ve misunderstood anything. Please feel free to reply at any time. Thank you for your cooperation and support. 

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