Can't log into Outlook after MS update

Since Outlook still works on the phone, the mailbox and provider settings are likely fine. The problem is on the laptop in Outlook after the update.

Try this in order:

1. Update Outlook first
   • Open Microsoft Store.
   • Go to Downloads and updates and select Get updates.
   • Restart Outlook and try adding the account again.
2. Reset New Outlook local sign-in/cache data
   • Completely close Outlook.
   • Press Windows + R, enter %localappdata%\Microsoft, and press Enter.
   • Delete the Olk and OneAuth folders.
   • Start Outlook again and try to add the account.
   • This removes local Outlook state and cached authentication data so Outlook can rebuild it.
3. If using New Outlook, add the account with manual IMAP settings
   • In New Outlook, go to Settings > Accounts > Email accounts > Add account.
   • Enter the email address and choose IMAP.
   • Select Show more and turn off Use recommended settings.
   • Enter the exact IMAP and SMTP server settings from the email provider.
   • If prompted to sync the IMAP account to Outlook, select Continue.
4. If using Classic Outlook and it never prompts correctly for password
   • During IMAP setup, make sure Require logon using Secure Password Authentication (SPA) is unchecked.
   • If Outlook still does not prompt correctly, create the account again:
     1. Open Control Panel.
     2. Select Mail.
     3. Select Email Accounts.
     4. On the Email tab, select New.
     5. Enter the name, email address, and password, then complete setup.
5. If Classic Outlook keeps asking for password or stopped working after a password change
   • Close Outlook.
   • Open Credential Manager from the Start menu.
   • Go to Manage your credentials > Windows Credentials.
   • Under Generic credentials, locate entries starting with MicrosoftOffice16_Data:OAUTH2.
   • Removing the affected cached OAuth credential can force Outlook to prompt for sign-in again.
   • After a password change, it can also take about one hour for the OAuth token to expire before Outlook prompts again.
6. Verify the account settings in Classic Outlook
   • Open Control Panel > Mail > Email Accounts.
   • Select the affected account and choose Change.
   • Confirm the incoming and outgoing mail server settings match the provider.
   • Under Logon Information, confirm the full email address is used as the username and that the password is correct.
   • If the provider uses two-factor authentication, use the generated passcode instead of the normal password.
7. If Outlook still cannot connect, create a new Outlook profile
   • Exit Outlook.
   • Open Control Panel > Mail.
   • Select Show Profiles > Add.
   • Create a new profile and add the email account.
   • Set Always use this profile to the new profile.
   • This is often the cleanest fix when an update leaves the Outlook profile in a bad state.

About the missing mail and files:

• The available guidance here covers reconnecting Outlook and resetting local Outlook state.
• Deleting Olk and OneAuth only removes local Outlook cache/authentication data and Outlook recreates it.
• If mail is still visible on the phone or in webmail, it is usually still on the mail server and can resync after the account reconnects.

If the issue started because the laptop switched into New Outlook and Classic Outlook is preferred, reinstalling Classic Outlook may be necessary in some cases.

References:

• Troubleshoot Outlook email setup
• Users get errors 0x800CCC0E & 0x800CCC0F synchronizing Gmail and Yahoo accounts in classic Outlook
• Change or update email account settings in Outlook for Windows
• Outlook doesn't connect or web services don't work after migration to Microsoft 365
• How can I add my Xfinity mail account to the New Outlook? - Microsoft Q&A
• Error Starting Outlook Since Update - Microsoft Q&A
• i cannot login into outlook on computer, but I can receive emails on my phone. - Microsoft Q&A