Translating messages while composing

I’m writing a message to someone who reads a language I don’t know. How can I translate my message to another language before sending it?

Mailspring currently supports automated translation of messages written in English into Spanish, Russian, simplified Chinese, French, and German using the Yandex Translation API.

To translate a message, first write your draft. Then, click the Translation icon at the bottom of the message window and choose your target language.

The translation plugin will translate the body of a single email and the signature only—not the full thread history.