Inbox folder size out of control

I have an inbox set for 1000 messages. At last check It is over 20,000 messages. It is an account accessed via POP. This was not a problem with earlier versions. In addition I have 4 accounts that I check and have the same issues with all.

I have set the “Local Folder Size” to different message counts and refreshed frequently, to no avail. My reasons for using POP and not IMAP are not the issue here. I am just looking for a way to fix a problem that was not a problem previously.

Thank you

Hi fellow members,
I have the same issue as tweiner. Currently I am at ‘only’ 5,000 messages, but since the last big update this has been slowing down my inbox tremendously. It takes K9 a minute or more to open the folder - and this basically happens almost every time I open or switch to the app.
Is there anything that could be done?
Thank you guys!

If asking what you as the user can do specifically: You could create a few subfolders and sort your inbox…

I have about 20,000 mails Ind my inbox, however sorted into 12 subfolders.