Setting an Out of Office on Behalf of Someone Else (Microsoft 365)

Managing automatic replies when a team member is unavailable

When Would You Need to Do This?

There are several situations where you might need to set an automatic out-of-office reply on someone else’s mailbox: they are off sick and did not have time to set one, they have left the company, they are on long-term leave, or they have simply forgotten.

As an admin, you can do this from the Microsoft 365 admin centre without needing to know their password.

How to Set an Out of Office

Step 1: Open the Exchange admin centre

• Sign in to admin.microsoft.com.
• In the left menu, under Admin centres, click Exchange.
• This opens the Exchange admin centre where you manage all email-related settings.

Step 2: Find the mailbox

• In the Exchange admin centre, go to Recipients > Mailboxes.
• Search for the person’s name and click on it.

Step 3: Set the automatic reply

• Click on the Others tab (or Manage mail flow settings depending on your version).
• Find Automatic replies and click Manage.
• Toggle automatic replies to On.
• Type the message you want people to receive. Keep it simple and helpful.
• You can set a start and end date if the absence is temporary.
• Choose whether to send replies to people outside your organisation as well.
• Click Save.

👉 Tip: For leavers, set the automatic reply to run indefinitely and include who to contact instead. After a few months, when emails to the old address have tailed off, you can forward the mailbox to someone else and remove the auto-reply.

Doing This Through Outlook (Alternative Method)

If you have full access to someone’s mailbox (for example, through delegation), you can also set their out-of-office directly in Outlook. Open their mailbox, go to File > Automatic Replies, and fill in the message. However, the admin centre method above is generally easier and does not require you to open their mailbox.