Outlook Web App (OWA) — Complete Guide to Microsoft 365 Webmail

Outlook Web App (OWA) — Complete Guide to Microsoft 365 Webmail

Outlook on the web (OWA) lets you access your Microsoft 365 email, calendar, and contacts from any browser — no app installation required. This guide covers everything from logging in and composing email to managing your calendar, configuring settings, and using advanced features.

Accessing Outlook on the Web

1. Open a browser and go to outlook.office.com.
2. Enter your Microsoft 365 email address and click Next.
3. Enter your password. If MFA is enabled, approve the sign-in in your Authenticator app or enter your SMS code.
4. Your inbox will load. The interface has three main columns: folder panel (left), message list (centre), reading pane (right).

Tip: You can also reach OWA from the Microsoft 365 home page at office.com → click the Outlook icon.

Email — Key Tasks

Composing and sending email

1. Click New mail (top-left).
2. Add recipients in the To field. Start typing a name to search the address book.
3. Add a subject, write your message, and click Send.
4. Use CC (carbon copy) for recipients who should be kept informed, and BCC for recipients whose addresses should remain hidden from others.

Formatting messages

• The formatting toolbar appears at the bottom of the compose window. Use it to change font, size, bold, italic, lists, and indentation.
• To switch between the simple text editor and the full HTML editor, click the three-dot menu (…) at the bottom of the compose window.

Attaching files

• Click the paperclip icon (or drag and drop a file) to attach from your device.
• Click the cloud icon to attach from OneDrive — this sends a sharing link rather than a copy, which is useful for large files.

Creating email rules

1. Click the settings cog ( ⚙ ) → search for Rules → click Inbox rules.
2. Click + Add new rule.
3. Name the rule, set the condition (e.g. from a specific address), and set the action (e.g. move to folder).
4. Click Save.

Setting up automatic replies (out of office)

1. Click the settings cog → search for Automatic replies.
2. Toggle Automatic replies on.
3. Optionally set a date range.
4. Write your reply for internal senders and, if required, a separate reply for external senders.
5. Click Save.

Searching email

• Use the search bar at the top to search by keyword, sender, subject, or date range.
• Click the filter icon in the search bar to refine results — useful for finding attachments or emails from a specific date.

Accessing Shared Mailboxes in OWA

1. Right-click Folders in the left panel.
2. Click Add shared folder or mailbox.
3. Type the shared mailbox address and click Add.
4. The shared mailbox appears in the folder panel below your own mailbox.

To open a shared mailbox in a separate browser tab (full view):

1. Add ?login=<shared-mailbox-address> to the OWA URL, or use the direct URL: https://outlook.office.com/mail/<shared-mailbox-address> if permitted by your admin.

Calendar

Viewing and creating events

1. Click the calendar icon in the left navigation bar.
2. Use the view buttons (Day, Work week, Week, Month) to switch layouts.
3. Click any time slot to create a new event, or click New event at the top.

Inviting attendees and checking availability

1. In the new event panel, add attendees in the Invite attendees field.
2. Click Scheduling assistant to see a grid showing everyone's free and busy times.
3. Select an available time slot and click Done.

Sharing your calendar

1. Right-click your calendar in the left panel → Share calendar.
2. Enter the recipient's email address.
3. Select the permission level: Can view when I'm busy, Can view all details, or Can edit.
4. Click Share.

Adding a shared calendar

1. Click Add calendar in the left panel → Add from directory.
2. Search for the person or resource and select their calendar.

Contacts (People)

• Click the people icon in the left navigation bar to access your contacts.
• Click New contact to add a personal contact.
• The Directory tab shows all users in your organisation's Global Address List (GAL).

OWA Settings

Access all settings via the cog icon ( ⚙ ) → View all Outlook settings.

Keyboard Shortcuts

Enable keyboard shortcuts at Settings → General → Accessibility if they are not working.

Troubleshooting OWA

OWA won't load or shows an error

• Try a different browser or clear your browser cache and cookies.
• Disable browser extensions (particularly ad blockers) — these can interfere with OWA.
• Try the OWA Light version: add ?layout=light to the URL.
• Check status.office.com for any known service issues.

Emails not appearing in OWA but arriving in Outlook desktop

• Refresh the page (F5).
• Check the Other tab if Focused Inbox is enabled.
• Confirm no rule is moving messages automatically: Settings → Mail → Rules.

Cannot open or send attachments

• Check the attachment is under the 25 MB limit for email attachments. Larger files should be shared via OneDrive.
• If a PDF or document won't preview, try downloading it instead of opening in-browser.

OWA keeps signing me out

• At the sign-in screen, tick Stay signed in to extend your session.
• Admins may have set a session timeout policy — check with your IT admin if this persists.

Related Guides

• Exchange Online — Email Flow, Forwarding & Troubleshooting
• Shared Mailboxes & Mailbox Permissions in Microsoft 365
• Distribution Lists & Microsoft 365 Groups
• Getting Started with Microsoft 365

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