How to change the Microsoft Bookings sender email address

Why "Send customer replies to" didn't fix it#

Under Business information there is a field called Send customer replies to. Microsoft describes it as the address "where email replies to booking confirmations and reminders should be forwarded". It sets the reply-to header, not the sender.

In an accepted 2020 Microsoft Q&A answer, the explanation was that Bookings "will not change it": the From address is the mailbox's primary SMTP address, and only an admin can change that. The Bookings FAQ says sender addresses are "controlled and managed at the Microsoft 365 settings level". A 2023 Q&A thread asking the same thing got an answer about editing the calendar's user, which doesn't change the address at all.

Fill the field in anyway, so replies reach an inbox someone reads.

Fix an existing booking page#

This is done in Exchange Online PowerShell. The Teams admin article on the Bookings app gives this command for moving a booking mailbox off the default domain:

Set-Mailbox -Identity YourBusiness@contoso.onmicrosoft.com `
  -WindowsEmailAddress YourBusiness@contoso.com `
  -EmailAddresses YourBusiness@contoso.com

Before running it:

1. Confirm the domain is verified in the Microsoft 365 admin center under Settings → Domains, and that SPF, DKIM and DMARC are in place for it. Otherwise the new sender can still fail authentication. The checks are on Bookings emails going to junk or bouncing.
2. Check the mailbox's current addresses with Get-Mailbox YourBusiness@contoso.onmicrosoft.com | Format-List EmailAddresses. Passing a single value to -EmailAddresses replaces the whole list. If you want to keep the old address as a secondary alias, include it too, for example -EmailAddresses SMTP:YourBusiness@contoso.com,smtp:YourBusiness@contoso.onmicrosoft.com (uppercase SMTP: marks the primary).
3. Pick the address customers will see, such as appointments@ or book@. It appears on every email.
4. Expect the booking page link to change. The public URL is built from the same mailbox address. Community reports say the old link redirects, but update links on your website, in email signatures and in ads. See changing the Bookings page URL for the caveats.
5. Make a test booking with an external address (Gmail or Outlook.com) and check the From line.

If you run Exchange hybrid, Microsoft recommends testing mail flow between on-premises Exchange and Exchange Online after the change.

Set the domain for new booking pages#

To stop new pages getting an onmicrosoft.com address, an admin sets the domain Bookings uses for new booking mailboxes in the OWA mailbox policy:

Get-OwaMailboxPolicy -Identity OwaMailboxPolicy-Default | Format-List BookingsMailboxDomain
Set-OwaMailboxPolicy -Identity OwaMailboxPolicy-Default -BookingsMailboxDomain "contoso.com"

To use a different domain for some people only, create a separate policy with New-OwaMailboxPolicy, set -BookingsMailboxDomain on it, and assign it with Set-CASMailbox -OwaMailboxPolicy. The Microsoft Learn article on custom domain support covers both, and notes that the steps assume no other OWA policies exist in your tenant.

The same article is explicit that "this change will not impact shared booking pages that have already been created". A Feedback Portal idea asking for the policy to apply to existing pages had 18 votes and was open as of September 2026, so existing pages still need the Set-Mailbox step above.

If you have no admin access#

Small tenants set up through a hosting provider (GoDaddy is a common example in the Q&A threads) often don't give the owner easy access to Exchange PowerShell. Ask whoever manages the Microsoft 365 subscription to run the change. The other route is to fix the default domain first and then delete and recreate the booking page, but deletion is permanent and also needs admin rights.

Why it's worth doing#

The best-practices article for shared booking pages says using the default domain "may cause Bookings email notifications to land in recipients' spam/junk folders", and several Q&A threads report confirmations rejected outright with 550 5.7.1. If that's the symptom you're chasing, start with the deliverability checks. If some customers get nothing at all, work through customers not receiving confirmations.

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