How to Set Up Outlook on Your Computer or Phone

Category: Microsoft 365 · Audience: Client & Internal · Updated: March 2026

Connect your Microsoft 365 email to Outlook on desktop, mobile, or the web. This guide covers all three and includes troubleshooting for common setup issues.

Which Version Should I Use?

• Outlook desktop app (Windows/Mac) — Best for full-featured daily use. Supports offline access, calendar, contacts, and shared mailboxes.
• Outlook mobile app (iPhone/Android) — Best for email on the go. Push notifications, calendar, and focused inbox built in.
• Outlook on the web — No installation needed. Go to outlook.office.com and sign in with your work email and password. Works from any browser.

Setting Up Outlook Desktop (Windows)

1. Open Outlook — If it's a fresh install, the setup wizard starts automatically. If Outlook is already open, go to File → Add Account.
2. Enter your work email address — Type your full Microsoft 365 email (e.g. yourname@yourbusiness.com.au) and click Connect.
3. Sign in — Enter your password when prompted. If MFA is enabled, approve the sign-in on your phone.
4. Wait for setup to complete — Outlook will configure your mailbox automatically. This may take a few minutes depending on mailbox size.
5. Done — Your email, calendar, and contacts will sync. Shared mailboxes and Teams calendars will appear if configured by your administrator.

Tip: If Outlook asks you to choose between Exchange, Microsoft 365, or IMAP — always select Microsoft 365 or Exchange. Never select IMAP for a Microsoft 365 account.

Setting Up Outlook Mobile (iPhone / Android)

1. Download the Outlook app — Search for "Microsoft Outlook" in the App Store or Google Play Store.
2. Open the app and tap "Add Account" — Enter your work email address.
3. Sign in and approve MFA — Enter your password, then approve the MFA prompt if enabled.
4. Allow notifications — Enable notifications to receive email and calendar alerts.
5. Done — Your inbox, calendar, and contacts will sync automatically.

Good to know: The Outlook mobile app supports multiple accounts. You can add personal and work accounts in the same app and switch between them.

Setting Up Outlook Desktop (Mac)

1. Open Outlook for Mac — Go to Outlook → Settings → Accounts → Add Account (or the setup wizard on first launch).
2. Enter your work email address and click Continue.
3. Sign in with your Microsoft 365 credentials — Approve MFA if prompted.
4. Done — Outlook for Mac syncs email, calendar, contacts, and shared mailboxes.

Common Issues

"Outlook keeps asking for my password"

This usually means the stored credentials are stale. Go to Windows Credential Manager (search "Credential Manager" in Start), find any entries related to Microsoft or Outlook, and remove them. Restart Outlook and sign in again.

On Mac, open Keychain Access, search for "Office" or "Microsoft", delete the related entries, and relaunch Outlook.

"My emails aren't syncing"

Check your internet connection first. If connected, try clicking Send/Receive All Folders (desktop) or pull down to refresh (mobile). If the issue persists, remove and re-add the account.

"Shared mailbox isn't showing"

Shared mailboxes auto-map in Outlook desktop if your admin has configured it. If it's not appearing, go to File → Account Settings → Account Settings → Change → More Settings → Advanced → Add and enter the shared mailbox address. Restart Outlook.

🔒 Internal Note (Technicians)

For shared mailbox auto-mapping issues, check Exchange Online PowerShell:

Get-Mailbox -Identity "shared@domain.com" | Format-List AutoMapping

If a user was added with Add-MailboxPermission without -AutoMapping $true, auto-mapping won't work. Re-add with: Add-MailboxPermission -Identity "shared@domain.com" -User "user@domain.com" -AccessRights FullAccess -AutoMapping $true

For Outlook profile corruption (repeated password prompts, sync failures), create a new Outlook profile via Control Panel → Mail → Show Profiles → Add.

Need help? Call 07 3523 3660 or submit a ticket at atssystems.com.au/support/ticket/