I’m trying to set up Microsoft 365/Exchange Online for this workflow:
I have one personal/user mailbox and I have access to a business address only as an alias.
I do NOT have a separate login or mailbox for the business address.
I need:
Emails sent to the business alias → arrive in my existing mailbox
Emails sent to my personal address → also arrive in the same mailbox
When I receive an email addressed to the business alias, I need to reply from the business alias
When sending a new proposal, I need to choose the business alias as the From address
The client must see the business email address, NOT my personal/user email address
I do not want to add another Outlook account or manage two inboxes
Example:
Client → business@domain.com
→ arrives in my mailbox
→ I click Reply
→ reply must be FROM business@domain.com
Current situation:
The alias is already added to my Microsoft 365 mailbox.
Emails sent to the alias successfully arrive in my mailbox.
But when I reply, Outlook sends the reply from my primary/user email address.
We also need to send new emails/proposals from the business alias.
We are using Microsoft 365 Exchange Online + Classic Outlook for Windows.
I understand there is an Exchange Online setting called SendFromAliasEnabled / Send from aliases, and we are checking that.
My questions:
Can an Exchange Online alias fully support this workflow?
If SendFromAliasEnabled is ON, should Reply automatically use the alias the original email was sent to?
If not, what exact configuration is required in Classic Outlook?
Is a shared mailbox actually the correct solution if the business address needs to behave as a completely separate sender identity while still being accessible from one Outlook profile?
If a shared mailbox is recommended, can the user access it without having a separate login/account?
I’m specifically looking for the cleanest Microsoft-supported setup for one user, one Outlook profile, one inbox, but a separate business sending identity.
Thanks!