Microsoft 365 setup guide: first-time login, MFA and Outlook setup

Why we wrote this

Every new starter at every one of our clients goes through the same first day: a new Microsoft 365 account, a temporary password, and a set of instructions that assume you already know what to do. Then Microsoft asks you to set up multi-factor authentication and things get confusing quickly.

So we wrote it down. The guide below is what we hand to every new user we onboard. It covers the sign-in, the password change, the Microsoft Authenticator setup, and getting Outlook working on your phone or iPad. If you follow it in order you will be up and running in about fifteen minutes.

If your business is thinking about switching Microsoft 365 provider, or you are a business owner reading this because a member of staff is stuck, the same instructions apply. Send them the link and get on with your day.

What Microsoft 365 gives you

Microsoft 365 is the umbrella name for a set of services your business pays for. Depending on your licence, you may get:

• Email and calendar in Outlook
• Microsoft Teams for meetings, chat and calls
• Word, Excel and PowerPoint on your computer, phone and tablet
• OneDrive for storing your work files in the cloud
• SharePoint for team files and intranet
• Other apps your organisation has chosen to enable

Once your account is set up, the same email address and password work across all of them.

Before you start

Gather these four things so you are not hunting for them halfway through:

• A computer connected to the internet.
• A mobile phone connected to the internet.
• Your Microsoft 365 email address (usually looks like firstname.lastname@yourcompany.co.uk).
• The temporary password supplied for your account.

The temporary password is exactly that: temporary. Microsoft will ask you to create a new one during your first sign-in.

Step 1: Sign in for the first time

1. Open Microsoft Edge, Google Chrome or Safari on your computer.
2. Go to portal.office.com.
3. Enter the Microsoft 365 email address supplied for your account, then select Next.
4. Enter the temporary password exactly as supplied, then select Sign in.

If the password is not accepted, check capital letters, lower-case letters, numbers and symbols carefully. Passwords are case sensitive. If it still does not work, email help@initialit.co.uk or call 01543 524 594.

Step 2: Create your new password

Microsoft will ask you to replace the temporary password before you can continue.

1. Enter the temporary password in the Current password box.
2. Create a new password and enter it in the New password box.
3. Enter the same new password again in the Confirm password box.
4. Select Sign in or Submit.

How to make your password strong

• Use a long password that is difficult for anyone else to guess. Length matters more than complexity.
• Do not use your name, birthday or the word “password”.
• Do not reuse a password you already use for another account.
• Do not write it down where anyone else can find it. Use a password manager if you can.
• Do not share your password with anyone. Nobody at Initial IT will ever ask for it.

A quick word about your phone

Your phone can be a personal one or a company one. Either works.

When you install Microsoft Authenticator, no data is stored on the phone. All Authenticator does is generate a random number that you approve when you sign in. Your emails, files and messages never touch the phone from that app.

Where it changes is if you also install Outlook, Teams or OneDrive on your phone. Those apps do store work data on the device: your email, calendar, files and Teams messages. On a company phone that is normally fine. On a personal phone it is a decision to make with your employer.

If you would rather not put work apps on a personal phone, Microsoft Authenticator on its own is enough to satisfy the MFA requirement. You can then use your work laptop or a work-issued device for email, Teams and files.

Step 3: Set up multi-factor authentication

Multi-factor authentication (usually shortened to MFA) adds a second safety check when you sign in. After you type your password, Microsoft will ask you to approve the sign-in from an app on your phone. Even if someone else learns your password, they cannot get into your account without your phone.

When you finish the password step, Microsoft may show a screen that says More information required. This is expected. It is Microsoft prompting you to set MFA up.

Install Microsoft Authenticator

1. On an iPhone or iPad, open the App Store. On an Android phone, open the Google Play Store.
2. Search for Microsoft Authenticator and install the app. It has a padlock icon with a blue and orange square around it.
3. On the computer, select Next on the More information required screen until a square QR code appears.
4. On the phone, open Microsoft Authenticator and tap the plus button or Add account.
5. Choose Work or school account, then choose Scan QR code.
6. Point the phone camera at the QR code shown on the computer.

Complete the test

1. On the computer, select Next.
2. Microsoft will display a two-digit number on the computer.
3. Open the Authenticator notification on the phone, enter that same number and select Yes or Approve.
4. On the computer, select Next, then Done.

Your temporary password is now replaced and MFA is set up. Next time you sign in, use your new password and approve the request in Microsoft Authenticator.

Step 4: Access Outlook on your phone

The Microsoft Outlook app is the recommended way to get your email and calendar on a phone.

On an iPhone

1. Open the App Store and search for Microsoft Outlook.
2. Install and open the Outlook app.
3. Select Add Account.
4. Enter your Microsoft 365 email address and select Continue.
5. Enter your new password when prompted.
6. Approve the sign-in request in Microsoft Authenticator if Microsoft asks for it.
7. Allow Outlook to send notifications if you want alerts for new email and calendar reminders.

On an Android phone

1. Open the Google Play Store and search for Microsoft Outlook.
2. Install and open the Outlook app.
3. Select Add Account.
4. Enter your Microsoft 365 email address and continue.
5. Enter your new password.
6. Approve the sign-in request in Microsoft Authenticator if prompted.
7. Allow notifications if you want email and calendar alerts.

Step 5: Access Outlook on your iPad

The steps are almost identical to the iPhone.

1. Open the App Store on the iPad.
2. Search for Microsoft Outlook, then install and open the app.
3. Select Add Account.
4. Enter your Microsoft 365 email address and your new password.
5. Approve the MFA request in Microsoft Authenticator when prompted.
6. Allow Outlook to synchronise your email and calendar.

Other Microsoft 365 apps

You can also install Microsoft Teams, Word, Excel, PowerPoint and OneDrive on your phone or tablet. Sign in to each one with the same Microsoft 365 email address and new password. MFA will not need setting up again, the Authenticator app will pop up whenever it is needed.

Step 6: Access another mailbox in Outlook Online

Sometimes you’ll be given access to a mailbox that isn’t your own. A shared inbox like info@yourbusiness.co.uk, a colleague’s mailbox while they’re off, or a project mailbox everyone on the team can see. This is how you open one of those in your web browser using Outlook Online.

Before you start, your Microsoft 365 admin (that is us, or whoever manages your tenant) needs to have granted you permission on the other mailbox. If you try the steps below and it says you don’t have access, that permission has not been set yet. Drop us a line and we’ll sort it.

1. Open your web browser and go to https://outlook.office.com.
2. Sign in with your own Microsoft 365 account (not the mailbox you are trying to open).
3. Once your own inbox has loaded, click your profile picture or initials in the top right corner.
4. Choose Open another mailbox from the menu.
5. In the box that appears, start typing the email address of the mailbox you want to open. Suggestions pop up as you type. Pick the right one.
6. Click Open.

The other mailbox opens in a new browser tab, kept completely separate from your own. You can leave both tabs open side by side and switch between them whenever you need to.

Sending as, or on behalf of, another mailbox

If you have send as permission on the mailbox, a new email from that second tab will send from the mailbox’s address exactly as if the mailbox owner sent it. If you only have send on behalf permission, the recipient will see something like “Your Name on behalf of Shared Mailbox” in the from line. Both permissions are set at the tenant level; if sending is not behaving the way you expect, that is what to check.

If it says you do not have permission

Two things usually cause this. First, permission genuinely has not been granted yet, and your admin needs to add you to the mailbox. Second, permission has been granted but has not yet made it through Microsoft’s back end (this can take up to an hour, occasionally longer). If it has been more than a couple of hours and you still cannot open it, get in touch.

Troubleshooting

Frequently asked questions

A note for business owners reading this

If this guide is landing with your team more often than you would like, that is usually a sign that your Microsoft 365 setup is missing the guard-rails that make new-starter onboarding painless: proper Conditional Access, sensible sharing defaults, retention policies, a written Acceptable Use Policy, and Intune enrolment so new devices configure themselves the first time someone signs in.

We do that as part of our managed IT service. Every company-owned device (laptop, desktop or phone) is enrolled into Microsoft Intune on day one, so the next new starter does not have to work through any of the above manually. They get given a device, they sign in, and they are ready.