Yes, this needs to be almost a priority. Because there's almost nothing to translate here.
There need to be these languages ASAP:
German, French, Italian, Spanish, Japanese. Also will highly appreciate Russian, and other european languages, as well as Chinese - as for 2 billion people out there speaking it. :)

Bonjour effectivement en FRANÇAIS .

oui en français merci
pour free

I think the best option would be to let users contribute translations. There are online services for the purpose. I can do ukrainian with love.

Permitan que ayudemos a traducir , es algo indispensable para que el proyecto avance y podamos promocionarlo.

German, pls

More languages???

Perhaps all languages: include Dutch
And Pay option from iDeal or Direct debits

Yes, french, german & italian would be great in Switzerland.

SPANISH is the second language in the US and 400 million people communicate in this language worldwide. This number of speakers is about twice the number of those that speak French.

Please , support Arabic language .

Chinese, please.

That's it!. I've have just suggest to activate a transifex or pootle service for that. Many of us could translate ProtonMail to our languages.

german

Portuguese Brazil, pleaseeeeee. ;)

Oh! This is planned now. That’s great.

I think it will be great to have another languages supported except english.
An i18n system may be possible ?

yes ! support Persian please :)

It would be a good idea if protonmail supports other langauges such as Arabic etc...
Privacy concerns many people in the Middlie East, for that reason having the arabic option in protonmail service will do the work

Sincerely, a random Arabian

multilinguale -> German as well please :-)