[Users] spell checker -- how to enable?

[Gil Weber]

Hello. I am using Claws-Mail 3.17.5 with Mint 19.0 Cinnamon (64 bit).
It's working fine except that I seem to have lost the spell checker. (At
least I think (??) I remember that it used to work -- but not sure.
Brain freeze I am afraid.) 

Sorry that I can't figure a simple way to check the archives for help,
so I'm asking here...

How do I enable the spell checker? 

(By the way, when I look in the Mint Software Manager I see that 
the following are allegedly installed (green check marks):

Aspell
Aspell-en

When I click on "Launch" for Aspell nothing happens. It also does not
appear in the Mint Menu of all applications. So I'm really not sure it
is on the computer. 

Thanks  :o)
Gil