Can I Give HR User Limited Access to Edit Out-of-Office Messages in Exchange Online?

You might need to create a custom admin role that allows this kind of access. I don't think you can achieve it with just a user role. However, be cautious; granting write permissions could lead to potential issues with third-party add-ins in Outlook.

If third-party solutions are still an option, check out our app! It has a role-based access control feature that lets you customize permissions for updating OOO messages, even restricting it to certain users. Here’s a quick video showing how it works!

I'm not sure if you can do this without adding the user as a delegate to the mailboxes they need to access. It's more of a management issue than a technical one; usually, users should set their own out-of-office replies through Outlook or OWA. But I get that as admins, we sometimes have to step in when someone is unavailable, like if they call in sick.

If you're looking to automate things, consider using a PowerShell script along with Microsoft Forms and a Flow. You can use the "Set-MailboxAutoreplyConfiguration" command to update the out-of-office settings programmatically. It could really streamline your process!