Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi Jovaras,
Once the languages have been selected in the Manage spellcheck languages, then the spellchecker will automatically use all the selected languages to spellcheck your email. It will give you suggestions in multiple languages.
If you just want to get suggestions in one specific language, I guess you can delete (temporarily) the other languages in the Manage spellcheck languages, then add then back once you're done.
Damien