Short answer
Almost always because the saved password is out of date or the outgoing server is missing its authentication setting. Confirm the password works by signing in to webmail first — that tells you whether the problem is the password or the configuration.
If webmail accepts it, remove the saved password in Windows Credential Manager and let Outlook ask again. Repeated prompts with a correct password almost always trace back to a stale stored credential rather than to the mail server.
Learn more
- Outlook keeps asking for the passwordStop Outlook repeatedly prompting for your email password: wrong username, stored credentials, Exchange auto-configuration and blocked logins.
- How to set up your email in OutlookAdd your Traxio mailbox to Outlook for Windows (new and classic) and Outlook for Mac using IMAP, with manual settings when auto-setup fails.
- How to change an email account passwordReset or change a mailbox password in DirectAdmin, then update it in every app so they don’t lock the account with failed logins.