Enigmail under XFCE (automatic encryption and decryption)

For long I have been very frustrated, that Enigmail wouldn'y remember my passphrase, prompting me for it every time I send or receive encrypted emails. I have searched and asked, but have not - until a few minutes ago - found the reason or a solution (this is probably due to my lack of knowledge).

I had no idea that this was related to the fact that I am running XFCE, which happens to be the case. By chance I discovered that under Settings -> Sessions and Startup -> advanced you can tick a box saying: launch GNOME service at startup. This triggers the Gnome keyring daemon to run upon boot.

I added my discovery to the manual: https://trisquel.info/en/forum/enigmail-does-not-ask-automatically-decrypt