Gmail Fix: Web Login Required (Failure)
Posted by jonathan at 5:07pm EST on 02/25/2009
E-mail Client: Thunderbird 2.x
Method of Access to Gmail: IMAP
SSL Enabled? Yes
Problem: If you’ve ever been using Gmail and accessing it via IMAP and run into the error “Web login required (failure),” you know that you’re not a happy Gmail user.
What’s the solution? Gmail » Settings » Browser Connection > Always use https

Then, close down the email client and start it back up. It should be all cleared up and you should be able to send mail again.

Rodney
Feb 25th, 2009
Only works for about 10 minutes, then the captcha site fix has to be done again. gmail imap is becoming increasingly frustrating and unusable
Jonathan Dingman
Feb 25th, 2009
I had this issue this morning, I did the steps above, and haven’t had an issue since.
After doing some research, even the captcha step didn’t help that much.
Hopefully the Gmail team will fix this sooner than later.
Angelo Patrick
Oct 4th, 2011
Hmmm problems in captcha. Thanks for Sharing.
Sorin
Oct 4th, 2011
hello, the same problem in my side but right now every think work ok.
Peso Ideal de la mujer
Oct 7th, 2011
old post but is very usefull gmail gmail its now perfectly for me
polocanada
Dec 4th, 2011
Here is the correct response:
Closed all mail clients you’re using to read Gmail messages. (If you
use one at work and one at home, please closed both.)
From the computer on which your logins are failing, visit
http://www.google.com/accounts/DisplayUnlockCaptcha
Enter your Gmail username and password, and the letters in the
distorted picture.
Once you have successfully logged in, restart your mail client and try
to download your mail.
Source:
http://groups.google.com/group/Gmail-Help-Logging-In-en/browse_thread/thread/c77b712fd8c09a09?pli=1