Outlook.com vs. Microsoft 365 vs. Exchange: Which Calendar Do You Have?

"Outlook" is a single name covering several different services, and which one you have changes what you can do—especially around sharing, publishing, and adding coworkers' calendars. This guide explains the three common account types, how to tell them apart in seconds, and why the distinction matters for the rest of your calendar tasks.

The three account types

How to tell which one you have

Check the email domain

• Ends in @outlook.com, @hotmail.com, @live.com, @msn.com → almost certainly a free Outlook.com account.
• Ends in your company or school domain → a work/school account, which is either Microsoft 365 or on-prem Exchange.

Check where you sign in

• You log in at outlook.com → Outlook.com (personal).
• You log in at outlook.office.com (or a company portal) → Microsoft 365 work/school.
• You log in through a company-specific server URL and there's no Microsoft cloud portal → likely on-prem Exchange.

Microsoft 365 vs. on-prem Exchange

Both use a company email address, so look closer:

• If your mailbox lives at outlook.office.com and your company uses Microsoft 365 / Office apps in the cloud → Microsoft 365 (Exchange Online).
• If your company hosts mail on its own Exchange servers and you don't have a Microsoft 365 cloud sign-in → on-prem Exchange. When unsure, ask your IT team; they'll know instantly.

Check in the app

• New Outlook / web: open Settings (gear) → Accounts → Your info / Mailbox, or look at the account list in the left rail.
• Classic desktop: File → Account Settings → Account Settings shows each account's type (e.g., Microsoft Exchange or Outlook.com).

Why it matters

The account type quietly determines what these other tasks can do:

• Sharing with specific people behaves differently across organizations and may be limited to free/busy for external recipients. See How to Publish and Share an Outlook Calendar.
• Publishing a public .ics feed is commonly enabled on Outlook.com but can be disabled by admins on Microsoft 365 and Exchange. See How to Get Your Outlook Calendar's Published .ics URL.
• Adding from the directory only works on work/school accounts, because personal Outlook.com has no org directory. See How to Add a Shared Calendar in Outlook.
• Locked settings. On managed accounts, an administrator may control working hours, sharing scope, and publishing—so a missing option usually means policy, not a bug.

Quick decision guide

1. Is your address @outlook.com/@hotmail.com? → Outlook.com (personal). Most sharing and publishing features are available to you directly.
2. Is it a company address you use at outlook.office.com? → Microsoft 365. Features exist but your admin sets the limits.
3. Company address with no Microsoft cloud portal? → On-prem Exchange. Capabilities depend on your server and IT policy.

Still unsure?

If you can't tell, the fastest answer is to ask your IT administrator, or check File → Account Settings in classic Outlook, which names the account type outright. Knowing it up front saves time on every sharing and publishing task that follows.

Whichever type you have, nocal brings your Outlook and Google calendars into one timeline — see how.