Setting up company-wide holidays in Microsoft 365

A relatively simple strategy for admins

If you're a Microsoft 365 admin looking to add holidays to all users' calendars (or a subset) without them needing to interact with a bunch of invites in their inboxes or add a .hol, here's one way to do it. Finding this took me a lamentable amount of time, so I wanted to document and share to hopefully minimize someone else's suffering.

You'll need to set up 2 mail flow rules in Microsoft Exchange as detailed here: Microsoft Learn. The first rule makes it so all events sent from a specific address of your choosing (such as admin@domain.com) are automatically accepted by receivers in your domain. The second rule immediately moves event invitations from that address to a user's deleted items. This allows someone with the ability to send from admin@domain.com to send event invitations that are automatically accepted without the user seeing or needing to interact with them. You may also want to set up the selected email address as a shared inbox so that it's easy to move or share access. Details on viewing and sending from a shared mailbox are available from Microsoft: open and use a shared mailbox in Outlook.

In addition, it is important to set up each event properly when sending. The company-wide holiday events are just normal meeting invitations with the following characteristics:

• Sent from [admin@domain.com] (if you're in Outlook, start in the [admin@domain.com] inbox and select New Items → Meeting—look at the scheduling assistant and ensure it says the right account name rather than your name to confirm)
• Title: [relevant holiday]
• All day event (on the appropriate day) (this should automatically remove any teams meeting links, but if it does not, choose Don't Host Online)
• Show As: Out of Office
• Reminder: 1 week (or whatever you prefer)
• Required attendees: [your attendees or group email]
• In the "Attendees" section of the ribbon, choose Response Options and uncheck Request Responses

If you send to a group that all users are automatically added to, all new accounts should get the holidays added to their calendars automatically as well.

In addition, this strategy can be used for sending out actual meeting invitations for things such as required all-hands meetings. I didn't use it for that and I think that's a little easier to find instructions to do if you're searching the far reaches of the internet, but hey, maybe you need it for both. I'm documenting it for holiday calendars because that's the purpose I personally spent hours trying to figure out!

last updated: 2026-05-06