How is skymail.de? Unable to find much information about them. Apart from their own site and this - https://www.bsi.bund.de/DE/Themen/Verbraucherinnen-und-Verbraucher/Informationen-und-Empfehlungen/Onlinekommunikation/E-Mail-Sicherheit/E-Mail-Checker/Anbieter-Check/skymail_de/skymail_de.html
How is skymail.de? Unable to find much information about them. Apart from their own site and this - https://www.bsi.bund.de/DE/Themen/Verbraucherinnen-und-Verbraucher/Informationen-und-Empfehlungen/Onlinekommunikation/E-Mail-Sicherheit/E-Mail-Checker/Anbieter-Check/skymail_de/skymail_de.html