Authentication Failure for Mail on iPhone

Not true. I have 2 yahoo emails and only one had "failed authentication" msg after I updated my IOS. The other was perfectly fine.

The update affected other password areas too, unrelated to email, which I resolved.

Taking the advice of "queenbeefastliveslow" plus whomever suggested re-starting phone solved it for me.

I actually feel a little stupid,, but I accidentally had put the machine in private mode. This caused a lot of of the issues I was having with signing in signing out. And the mail did the change from private mode to not private. So did this swap make the difference? I really can’t answer my own question but yet I believe that it not only made the difference but fixed all of my issues.

This worked! And me and technology have a rocky relationship. I’ve been locked out of email since 4/2. The advice of “queenbeefastliveslow” didn’t work on its own i had to shut down the phone for a couple of minutes then all those emails started flooding in. Good luck.

Here is the fix!

Go to i phone settings> Scroll down & click on apps> Scroll down & click on Mail app> Click on Mail accounts> Click the Mail account your error is referring to> switch the mail slider to off then back on. It will then prompt you to sign in, once signed in it should be fixed. If error is till occurring, once again make sure the mail slider is turned on.

Had this error for GMail. I fixed it by toggling the Mail off in the Mail settings for GMail, then back on and re-logged in. Then, I logged into the GMail account via the browser. I went to manage account, then Security. There was an error about an attempted login and it wanted me to confirm that it was me. I confirmed, and my email worked.

Generate an App Password

1. Open a web browser on your computer or phone and sign in to your Yahoo account.
2. Go to your Yahoo Account Security page. (You may need to search "Yahoo Account Security" if you can't find the direct link).
3. Click on Generate app password or Generate and manage app passwords.
4. From the dropdown menu, select "Other App" or a relevant option (like "iOS Mail").
5. Enter a name for the app (e.g., "iPhone Mail") and click Generate Password.
6. A unique, 16-digit password will be displayed. Copy this password immediately—you will not see it again.

Try the Official Yahoo Sign-in Helper (via Web Browser)

The most reliable way to reset your password is to use the official Yahoo recovery tool outside of the Mail app.

• Open Safari or any web browser on your iPhone.
• Go to the official Yahoo Sign-in Helper page (search for "Yahoo password reset" or navigate to login.yahoo.com/forgot).
• Enter your Yahoo ID, email address, or mobile number.
• Follow the on-screen prompts to receive a verification code (via text or alternate email) and set a new password.
• The in-app reset process can sometimes be less stable than the dedicated web-based recovery page.

Can’t get my emails and haven’t changed anything!

how do I correct for Authentication Failure for Mail on iPhone

Me too

How can I fix AUTHENTICATE invalid credentials for mail

Mine just did it on att I’m going to call customer care

What did you do to resolve the problem?

how do I correct for Authentication Failure for Mail on iPhone