my main mail account runs at Posteo, which is a privacy-friendly mail provider. Therefore, I have an existing key pair which I am using in Thunderbird and which is also used by my mail provider (i.e. mails on the server are encrypted with my key).
Now, I wanted to start using PEP on my Android phone. I exported my private and public key to my phone and tried to import it in PEP (by using Account → Settings → Privacy → Open PGP Compatibility → PGP Key Import from Filesystem). The imports seems to have worked since I can read the encrypted mail in my mail folder. However, when I'm sending mail it gets encrypted with the key which was generated by PEP, I guess, since it's not the public key that I've imported.
I can't seem to figure out how to tell PEP to use my imported key for encrypting mail. Also, the imported key (signature ends with 80) does not show up in the "Extra Key Management" section of the settings (screenshot attached).
If I'm trying to import my keys again, it yields an error:
"2021-01-02 10:27:46.626 6695-18278/? W/KeyImportPresenter$onKe: Couldn't set own key: CA375A62EEF7BCEBD5D11855B2EA254FD0B87E80
Thanks for your held and advice and happy new year :)