Tips on how to make Yahoo Mail working on Android Mail and K-9 Mail with IMAP
After spending so much time trying to get Free Yahoo Mail to work in my HTC Droid Incredible, I constantly getting username/login/password not correct or authentication failed…. blah blah blah error. Eventually, I got it to work. Therefore I want to post my experience here hoping to help someone out there who are facing the same hassle.

smallwei 9:54 pm on August 31, 2010
First of all, here are my settings:
Incoming IMAP mail server:
Username: [Your full email address]
Password: [Your email password]
IMAP server: imap.mail.yahoo.com
Security type: None
Port: 143
Outgoing SMTP mail server:
SMTP server: android.smtp.mail.yahoo.com
Security type: SSL
Port: 465
Require sign-in: checked
Authentication type: PLAIN
Username: [Your full email address]
Password: [Your email password]
Tips:
Now, in the perfect world, with the above information, everything should work. Unfortunately, I had to try some other things in order to make it work. I’m not sure exactly which one I tried actually made it work, therefore I list out all the things I tried:
1. Double check your password.
2. Use your computer browser, login and logout your yahoo mail account.
3. If you’re trying to setup using K-9 mail client with no success, trying setting it up with the default Android “Mail” program first to see if it works.
4. Some people said to turn off Wi-Fi, but I was able to get it to work on both 3G and Wi-Fi. You can try it without Wi-Fi first if still having issues.