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Get K-9 Material (unofficial) old version APK for Android
Un servizio gratuito e open-source client di posta elettronica materiale a base di K-9 Mail.
A free and open-source Material mail client based on K-9 Mail.
Source code: https://github.com/scoute-dich/K9-MailClient
For now, the app has the same features as K-9.