[Geary] Preferences: "Enable spell checking" does not appear

[Warren Post <warren copaninvest com>]

Hello,

I have geary-0.12.4-lp151.1.4.x86_64 installed from OpenSUSE 15.1's 
repository, running in Xfce 4.12. Geary's documentation states that the 
Preferences window should show me an "Enable spell checking" option, 
but it does not.
I am aware per the FAQ that Geary is designed for Gnome and I don't 
mind installing whatever I need to make this work. libenchant1 and 
desired myspell dictionaries were already installed before I installed 
Geary. In Geary's composer window I do see the book icon for spell 
checking, and upon clicking it I do see the installed myspell 
dictionaries.
My best guess is that spell check is ready to work and all I need to do 
is enable it. What should I be looking at to either make this option 
appear in Preferences or enable it some other way?
I only installed Geary yesterday but already like it a lot and want to 
make it my go-to mail client. Good job everyone.
--
Warren Post
https://www.linkedin.com/in/wpost