Description
Not as safe as an open-source client, like Thunderbird or SeaMonkey’s mail. Vivaldi has been hesitant to release their source code, and they actually released a page full of excuses about why they shouldn’t need to.
Edit: you changed the title/text, so my answer is… Thunderbird is the most private email client. Originally, this post was about Vivaldi
You need to provide more context in order get a proper answer.
What specifics you wanna know
Exactly ;)
What protocol are you using to connect to your mail service and what third-party apps do you need it to be compatible with? POP, IMAP, SMTP, or those protocols with various SSL/TLS implementations? Thunderbird will likely handle anything you throw at it, but I’m at a loss when you start talking about third-party apps without more info.
Thunderbird for desktop, K-9 Mail for Android.
