Just like 5.403, except with the old icon.

Note that this is NOT the offical K9 Mail App!!! It is my modification (rhialto/5.4-MAINT branch) which has reverted to the old icons. I don't even have an Android build environment; I used Travis CI to build and upload the result here. Then I signed it with a freshly made key.

You cannot simply update from the real K9 to my version. For one, the version number does not increase. For another, it is signed with a different key. You will (probably) have to do at least the following:

• Export settings and accounts
• De-install K9
• Re-install the ...signed.apk file. The second time around, I had to use adb install -r k9mail-release-signed.apk since the installer on my phone mysteriously didn't enable its install button.
• Import settings
• Re-enter all your passwords
• Re-affirm any certificates from the mail server.

Of course you don't get any automatic updates any more. I also do not guarantee to create new releases to keep up with the real version.