How to fix New outlook Invalid Credentials Intervention required when adding IMAP account?

Question

New outlook "Invalid Credentials Intervention required" when adding a new IMAP account to the new Outlook?

Answer 1

Hello,

Please use the password/code generated by the application to log in to your IMAP email account and see if you can access it.

https://learn.microsoft.com/en-us/answers/questions/4624282/invalid-credentials-interaction-required-when-addi?page=3#answers

Answer 2

The "Invalid Credentials – Intervention required" message in new Outlook when adding an IMAP account is typically caused by one of these issues:

1. The IMAP provider requires an app password instead of the normal account password.
2. The IMAP password contains Unicode characters that Outlook cannot handle.
3. There is a problem with an existing/expired app password for that IMAP account.

Use the steps below in order.

1. Check if the provider requires an app password Many third‑party providers (AOL, Yahoo, some ISP mail, iCloud, etc.) require an app password for IMAP access in Outlook instead of the regular sign‑in password.

• Sign in to the email provider’s webmail/portal. • Go to the security or account settings page. • Look for options like “App passwords,” “Third‑party app access,” or “App‑specific password.” • Generate a new app password for Outlook. • In new Outlook, add the IMAP account again and paste this app password when prompted for the password.

If using Gmail or iCloud, follow the provider‑specific guidance referenced in the Outlook documentation: • For Gmail: see “Add a Gmail account to Outlook for Windows.” • For iCloud: see “Add or manage an iCloud email account in Outlook.”

2. If already using an app password, recreate it If the IMAP account was working before and suddenly fails with “Invalid Credentials,” the app password may be invalid or expired.

• Log in to the IMAP provider’s webmail. • Go to Account Information > Security (or similar). • Delete the old app password (if shown) and create a new app password. • In new Outlook:

1. Go to File > Account Settings > Server Settings for that IMAP account.
2. Replace the existing password with the new app password.
3. Save and test send/receive.
4. Remove Unicode characters from the password If the IMAP password includes non‑ASCII characters (for example ä, ö, ü or other Unicode characters), Outlook can fail authentication.

• Change the email account password on the provider’s website to a password that uses only standard ASCII characters (letters A–Z, numbers, and basic symbols). • If the provider requires an app password, generate a new app password after changing the main password. • Re‑enter the new password/app password in Outlook when adding the IMAP account.

4. As a last resort, try POP instead of IMAP (if supported) If the provider supports POP3 and IMAP continues to fail, configure the account as POP3 in Outlook.

• Close Outlook. • Open Control Panel > Mail > Show Profiles > Add, and create a new profile. • Choose Manual setup or additional server types > Next. • Choose POP or IMAP > Next. • Enter the account details but select POP3 as the Account Type. • Enter the incoming (POP3) and outgoing (SMTP) server names from the provider. • Complete the test and finish the profile setup. • Set the new profile as the default in Mail > Always use this profile.

Note: POP3 downloads mail to the local computer and usually removes it from the server, unlike IMAP which keeps mail on the server.

If the account is Gmail and the error is specifically “Could not sign you in to Google – IMAP,” ensure Outlook is updated to a build that includes the fix and that “Enable optional connected experiences” is turned on under File > Office Account > Account Privacy > Manage Settings.

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References:

• Add an email account to Outlook for Windows
• Authentication fails when you use an IMAP server in Outlook 2016
• Outlook IMAP or POP server unexpectedly terminated the connection, and the server was interrupted
• Unable to add a Gmail account to Outlook "Could not sign you in to Google"
• Fix problems importing an Outlook .pst file
• Error, "You may need to make an app password," when you add an account or send/receive email from some third-party email accounts