Spell Checker in Mozilla Mail

I am a very picky person when it comes to
spelling in email, but Mozilla Mail (1.7.8) doesn't
seem to have a plugin, at least I couldn't
locate it.

I run SuSe Linux 9.3 with Kernel 6.

If Mozilla does in fact have a spellchecker, can someone please
tell me where I can downlosd it and locate the steps
to install it?

Thanks in advance,

salman