Problem Directory named "file:"keeps showing up.

I may have mentioned this earlier I cannot find the thread.

Using Debian Testing with some unstable packages, of course

It happens EVERY TIME I login to a different windowing manager: XFCE, XFCE, Plasma, Fluxbox, and probably others.

The structure of the directory is that of a mail directory:

===
./file:
/home
kevin/
.local/
share/
local-mail/
cur/
new/
tmp/

===

I have deleted kmail, and installed thunderbird... no change.

So what the {bad-word} is going on with my system?
It doesn't break anything, but this has been {upsetting} me for several months.

Has this happened to anyone else?
Does anyone have any suggestions to help me fix this?

Thank you for your time, and have a good day!