Add your Microsoft 365 work email to Outlook on a Windows PC, whether you use classic Outlook (the desktop app that comes with Microsoft 365 Apps) or the new Outlook for Windows. You only need your email address and password. Outlook finds the server settings for you.
Classic Outlook or new Outlook: which do I have?
Windows PCs can now have two different Outlook apps, and they look and behave differently:
| Classic Outlook | New Outlook for Windows | |
|---|---|---|
| How to recognise it | A File tab at the top left and a ribbon of buttons. Its icon says "Outlook (classic)" in the Start menu on newer installs. | No File tab. It looks like Outlook on the web, with a New Outlook toggle or a gear icon for Settings at the top right. |
| Which plans can use it | Business Standard and Business Premium (it is part of the Microsoft 365 desktop apps) | All plans, including Business Basic. It comes with Windows 11 and is free from the Microsoft Store. |
| Strengths | Full offline working, PST files, COM add-ins, VBA macros, mail merge, advanced rules | Fast, simple, the same layout as Outlook on the web, and it gets new features first |
Microsoft has said classic Outlook will remain supported for business customers until at least 2029, so there's no rush to switch if it works well for you.
Before you start
- Your Microsoft 365 email address and password. If you've just been given a temporary password, sign in once at office.com first to set your own password and complete any multi-factor authentication (MFA) set-up.
- Your domain must already be connected to Microsoft 365, including the
autodiscoverrecord that lets Outlook find your mailbox automatically. Your administrator (or Host Dada, if we manage your DNS) sets this up once. See Microsoft 365 DNS records on Host Dada nameservers. - For classic Outlook, Microsoft 365 Apps must be installed and signed in. See Install Microsoft 365 apps.
Set up classic Outlook
If Outlook has never been opened on this PC
- Open Outlook. Search the Start menu for Outlook (classic) (on some PCs it's listed as Outlook).
- Enter your email address. Type your full work address, such as
you@yourbusiness.co.uk, and select Connect. Don't open Advanced options, because you don't need to set anything manually. - Sign in. A Microsoft sign-in window appears. Enter your password and approve the MFA prompt on your phone if asked.
- Allow your organisation to manage this device? Windows may ask whether to let your organisation manage the device. For a personal or home PC, choose No, sign in to this app only. On a company PC, follow your administrator's instructions.
- Finish. Select Done. Outlook downloads your email, calendar and contacts. A large mailbox can take an hour or more to finish syncing the first time, but new email appears straight away.
If Outlook already has another account
- Open the File tab. Select File → Add Account.
- Enter your Microsoft 365 address and select Connect, then sign in as above.
- Restart Outlook if asked. The new mailbox appears in the folder pane under its email address.
Set up the new Outlook for Windows
- Open the new Outlook. Search the Start menu for Outlook (new), or in classic Outlook turn on the Try the new Outlook (or New Outlook) toggle at the top right.
- Add your account. On first launch, enter your work email address and select Continue. If Outlook already has an account, go to Settings (gear icon) → Accounts → Email accounts → Add account.
- Sign in with your Microsoft 365 password and complete MFA.
- Import settings (optional). If you switched from classic Outlook, the new Outlook offers to bring across your accounts and some settings. Accept, then check your signature and rules (see below).
To go back to classic Outlook at any time, turn off the New Outlook toggle at the top of the window. Both apps read the same mailbox in Microsoft 365, so nothing is lost when you switch.
What carries over between Outlook apps
Because your mail, calendar, contacts and server-side rules live in Microsoft 365 (not on your PC), they appear in every Outlook app, on your phone and in Outlook on the web. A few things are stored differently:
- Signatures: work-account signatures now sync through your mailbox in most cases, but check them after switching. See Add an email signature.
- PST files: classic Outlook opens and imports them fully. The new Outlook can import mail, calendar, contacts and tasks from a PST, but some PST features are still missing, so use classic Outlook for big archives.
- Add-ins and macros: COM add-ins and VBA macros only run in classic Outlook. The new Outlook supports web add-ins from the Microsoft Store.
- Shared mailboxes: in classic Outlook, shared mailboxes you have Full Access to usually appear automatically. In the new Outlook, add them under Shared with me in the folder pane. See Give someone access to your mailbox or calendar.
Settings at a glance
You shouldn't need to type any of these, but they're useful if someone asks.
| Setting | Value |
|---|---|
| Account type | Microsoft 365 / Exchange (chosen automatically). Don't choose IMAP or POP. |
| Username | Your full work email address |
| Sign-in | Modern authentication (Microsoft sign-in window, with MFA) |
| Autodiscover DNS record | CNAME autodiscover → autodiscover.outlook.com |
Troubleshooting
Outlook says "Something went wrong" or keeps looking for the server
Usually the autodiscover DNS record still points at your old email host. If your domain used Host Dada Email before, it may still point at the old mail platform. An administrator should change it to autodiscover.outlook.com. Allow up to an hour for the change to take effect, then try again. Meanwhile you can use Outlook on the web.
Outlook set my account up as IMAP
Remove the account and add it again, entering only your email address. If Outlook offers a choice of account type, pick Microsoft 365. IMAP connections to Microsoft 365 are blocked by security defaults, and they don't sync your calendar or contacts.
"Your account isn't licensed" or Outlook won't activate
Classic Outlook needs a Business Standard or Premium licence. Ask your administrator to check your licence under Users → Active users in the admin centre (see Add a user and assign a licence), or use the new Outlook, which works with Business Basic.
Outlook keeps asking for my password
This is the most common Outlook problem. See Outlook keeps asking for a password: how to fix and repair Outlook.
Last reviewed: October 2026
