In that 'Folders' menu, if you tap on the three-dot icon in the bottom right to get into that folder's options menu there's a 'Show folders...' option. Tap on that and that will show different options like 'All folders' '1st Class folders' and more. Depending on how you've previously set up your K9 Mail app's Settings >> Account settings >> Folders menu this allows you a lot of granular control on how different folders (and the respective messages they each contain) get displayed in the app. It sounds like at some point you selected the 'All folders' option (not the default) to be displayed.
An aspect to K9 Mail I like is it does have a lot of user interface options (even if both its settings menus are somewhat convoluted), you might find it worth reading through their documentation page on Folders: https://k9mail.github.io/documentation/folders.html
If it's a matter of you can receive email messages but not send them, check your settings in the Settings >> Account settings >> Sending Mail >> Outgoing server menu
but if you cannot receive or send anything, try re-setting your new password in Settings >> Account settings >> Fetching mail >> Incoming server menu, this should then reflect on both your account's IMAP and SMTP settings.
If you use a browser to go to https://mail.google.com and log into your account, are you able to send and receive email messages?
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.