535 5.7.8: Username and password not accepted (Gmail)
Gmail refused to let your app, printer or website sign in to send email. Your message was never sent.
Sign-in problem Your app or device couldn't sign in to your own mail server, so the message was never sent. Fix the sign-in settings.
What the bounce message looks like
The wording changes from one provider to another. These are typical examples:
535-5.7.8 Username and Password not accepted. For more information, go to https://support.google.com/mail/?p=BadCredentialsCommon causes
- You used your normal Google password. Gmail no longer accepts it from mail apps and devices
- A typo in the username: it must be your full Gmail address
- An old app password that stopped working after you changed your Google password
- A work or school account where the admin has turned off app passwords
How to fix it if you sent the email
- Turn on 2-Step Verification and create an app password, then use it in place of your password.
- If the app offers "Sign in with Google", use that instead.
- Check the full settings in the Gmail SMTP settings guide.
If you manage the receiving or sending mail system
- For printers and systems in Google Workspace, consider the SMTP relay service instead of signing in as a user.
Free tool: paste the full bounce into the bounce message decoder to get a plain-English reading of every code in it.
Questions people ask
- What does 535 5.7.8 mean?
- Gmail refused to let your app, printer or website sign in to send email. Your message was never sent.
- Is 535 5.7.8 a hard or soft bounce?
- Sign-in problem. Your app or device couldn't sign in to your own mail server, so the message was never sent. Fix the sign-in settings.
- Should I remove the address after a 5.7.8 bounce?
- No. The message never left your own mail server. Fix the sign-in or sender settings and send again.