Mullvad has operated public encrypted DNS (DoH) servers since 2022. They are unnecessary when using Mullvad VPN — traffic is already encrypted and Mullvad VPN's internal DNS handles all queries.
If you already use Proton Mail, I strongly recommend against using ProtonVPN because you’re coupling yourself too hard to Proton. At least, if your threat model is high risk
If you already use Proton Mail, I strongly recommend against using ProtonVPN because you’re coupling yourself too hard to Proton. At least, if your threat model is high risk