If captcha is enabled on your GMail account (and it is enabled by default), then GMail POP3 authentication will fail with this error (even though a correct login/password is provided)
**** Connected to pop.gmail.com:995 < +OK Gpop ready for requests from 22.214.171.124 c23pf1097242ibu.22 > USER firstname.lastname@example.org < +OK send PASS > PASS **** < -ERR [AUTH] Username and password not accepted.
To successfully authenticate with pop.gmail.com from an email client such as Outlook, Thunderbird, or an application using Chilkat one must first unlock captcha:
- From the computer on which your signins 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 signed in, retry running your application using Chilkat.
Note: Unlocking captcha is not required to access a GMail account via the IMAP protocol (imap.gmail.com).