How to Fix Outlook 2016 Setup Error for Office 365 Mailbox?

Sahil Verma
Sahil Verma | Updated On - 10 Aug 2022 |

Read time: 8 minutes

If you’re like most business owners, you rely on Microsoft Outlook to keep your calendar and email organized. But what do you do when you try to set up or configure Office 365 account in Outlook 2016 and get an error message? The error says, “cannot connect to server” and you are unable to access your mailbox. Many businesses are running into this issue, but don’t worry – we have a fix. In this post, we’ll walk you through the steps to set up your Office 365 mailbox in Outlook 2016. We’ll also show you how to fix the error that’s been popping up for so many people. So, let’s get started!

Fixing the Outlook 2016 Setup Error for Office 365 Mailbox

If you’re seeing Outlook 2016 setup errors when trying to configure your Office 365 mailbox, there are a few things you can try to fix the issue.

Checking for the Right Outlook Profile

  1. First, make sure that you’re using the correct Outlook Settings for Office 365. To do this, open Outlook and go to File > Account Settings.go to file account settings.
  2. From the drop-down menu, look for your Office 365 account or click on Change Profile.Click Change Profile
  3. Next, check that you’re using the correct Outlook profile. Tap on Account Settings again and select Manage Profiles.Tap on Account Settings
  4. Under the Mail Setup – Outlook window, click on Show Profiles.Click on Show Profiles
  5. Select the Outlook profile that matches your Office 365 account and checkmark the option Always use this profile. Tap on Apply and OK. Tap on Apply and OK

Disable Multi-factor Authentication for Office 365 Account

In this case, the Outlook 2016 Setup Error might occur if the Exchange administrator enabled multi-factor authentication (MFA). In response, the server returns an HTTP 456 authentication error.
Disable MFA for this account in Office 365 to resolve the issue. Here are the steps to do so.

  1. To access your Office 365 subscription, log into the Office 365 portal with your account.
  2. Click Admin on the portal’s main page.
  3. Go to the navigation pane, tap on Users and click on Active users.Click on active users
  4. Under the Active users pane, tap on More and go to the Multifactor authentication setup.Multifactor authentication setup
  5. Choose the affected user from the list and check the box.
  6. Tap on Disable from the Quick Steps menu. Click on Yes at last.Click on Yes at last

Recreate the OST File

If you’re still seeing Outlook 2016 setup errors, it’s possible that your Outlook data file is corrupted. To fix this, you can recreate a new local Outlook Data File.

  1. Access Outlook & tap on File. On the right side, click on Account Settings.Click on Account Settings
  2. In the next window, tap on the tab Data Files tab.tap on the tab Data Files tab
  3. Choose an account and click on Open File Location.click on Open File Location
  4. You need to exit Outlook but must keep the File Explorer dialog window open.
  5. Lastly, delete the OST file and close the File Explorer window. Restart Outlook and you are good to go.Restart Outlook

Update to the Latest Outlook/Office Version

To fix the Outlook 2016 setup error, you can also look to update Outlook to its latest version. Here is how to do so.

  1. Access Outlook and tap on the File menu.
  2. From the navigation pane, click on Office Account.click on Office Account
  3. Click on the option Office Updates and click on Update Now.Click on Update Now
  4. Let the update process be finished and your error might be resolved by now.

Update Windows

Windows Update is one of the universal methods to fix the basic errors of Outlook and Office 365. To fix the Outlook 2016 setup errors, try updating Windows with the steps below.

  1. Type Settings in the Search box, click it and go to Update & Security.Update  Security
  2. From the left side dashboard of Windows Update, tap on Check for Updates.
  3. When the new updates come up, tap on Install now.tap on Install now
  4. After a successful update, you can set up your Office 365 mailbox in Outlook 2016 easily and the Outlook 2016 setup error will be fixed.

If you continue to see Outlook 2016 setup errors, or if you have any questions, you need to contact the IT support team.

These are all the manual solutions to this Outlook Setup error for Office 365 Mailbox but to make things safer for us, it is essential to keep a backup of Exchange Online mailboxes. For this, it is recommended to use the Kernel Office 365 Backup Tool. This utility saves Exchange/Office 365 mailboxes in PST without Outlook and backs up archive/shared mailboxes & public folders.

Moreover, Moreover, this software allows you to take a backup of live Exchange mailboxes without interrupting your work and keep you away from the hassle if you accidentally delete user mailboxes in exchange online. Also, this tool is compatible with all versions of Windows.

Closing Notes

If you are encountering the Outlook 2016 setup error for Office 365 mailbox, we have some troubleshooting methods that may help. We understand how frustrating it can be when something doesn’t work the way it’s supposed to. So hopefully these tips will get your email up and running again in no time. To keep your issues sorted out, use the Kernel Office 365 Backup program and keep a backup of your Exchange Online mailboxes as an added layer of precaution for the future. Get started with this tool now as it is available for free online.