> Date: Saturday, January 30, 2016 04:24:28 -0800
> From: Ninjutsu Ryu <
ninju...@gmail.com>
>
> Hello everyone,
>
> Since about 6 hours ago, K9 no longer retrieves any email from my
> Yahoo account. I have not changed any of the settings. I can
> still send mail.
>
> The error message is:
> *Username or password incorrect. (Command: AUTHENTICATE PLAIN;
> response:
># 1# [NO, AUTHENTICATIONFAILED], (#AUTH401) Incorrect username or
> password.])*
>
> Under *Incoming server settings* I have:
> IMAP server:*
imap.mail.yahoo.com*
> Security: *SSL/TLS*
> Port: *993*
> Username : *???????@
yahoo.com*
> Authentication: *Normal password*
> Password:
> *[x] Auto-detect IMAP namespace*
>
> K9-Mail version: 5.007
> Device make: LGE
> Device model: LG-D722
> Android version: 4.4.2
>
Well, if you haven't changed any settings or updated K-9 in the last
6 hours I think you need to chat with your "friends" at yahoo to see
what they have done (this time).
You might first, however, try to log into your account via their
webmail interface to confirm that your password hasn't (been)
changed as that is the implication from their response.