Odoo Email Marketing

I use odoo12 ce. Emails sent from the email marketing module do not have the option to set the language of the email. $ {object.partner_id.lang} I read that there is a fixed English here. As a result e-mails, which are written in Hungarian, using characters with Hungarian accent, recive worse rating from spamassasin.(-2.299 MIXED_ES Too many es are not es) I read that by reaching into the code you can set it to another language. Does anyone have a solution?