Using New Outlook on Windows for personal email, calendar, and contact management
For an IMAP account in Outlook, this error is usually caused by one of these conditions:
- An app password is required
Some providers do not accept the normal account password in Outlook when extra security is enabled.
- If the mailbox is iCloud, create an app-specific password on the Apple Account website, then add the account again in Outlook using that app password instead of the normal password.
- If the mailbox is Yahoo, Outlook Desktop supports OAuth on supported builds and channels, so the normal password is used instead of an app password. If Yahoo app password generation is failing, this can be a provider-side issue.
- The IMAP account needs to be added manually
In classic Outlook, if automatic setup fails:
- Go to File > Add Account.
- Enter the email address.
- Select Advanced options > Let me set up my account manually.
- Choose POP or IMAP.
- Enter the password and continue.
- If setup fails, select Change Account Settings and enter the incoming and outgoing server settings from the email provider.
- Secure Password Authentication (SPA) may be blocking sign-in If Outlook does not prompt correctly for the password on an IMAP account, make sure Require logon using Secure Password Authentication (SPA) is unchecked.
- The password itself may be the problem
- Make sure the username is the full email address.
- Make sure the password is entered with the correct case.
- If the password was changed with the email provider, update it in Outlook.
- In Outlook 2016, IMAP authentication can fail if the password contains Unicode characters such as
ä,ö, orü. Changing the password to remove Unicode characters is the documented workaround.
- For Outlook for iOS only If the account password was changed, it must be changed on the email provider’s website first, then re-entered in Outlook for iOS. If sync still fails, delete and re-add the account.
If the account worked before reinstalling Outlook, the most practical path is:
- Confirm the mailbox still signs in on the provider’s webmail.
- Check whether the provider now requires an app password.
- Re-add the account with manual IMAP settings.
- Ensure SPA is unchecked.
- If using Yahoo, use the normal password on a build/channel that supports Yahoo OAuth.
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