Security support

My email provider will no longer accept polls from K9 mail because K9 doesn’t support anything beyond TTL 2.0. Is there support for higher levels of security?

In these cases letters and numbers are important to know what the actual issue is. “TTL 2.0” doesn’t sound right. Was it maybe “TLS 1.2”, “SSL 3.0”?

K-9 Mail doesn’t ship with a TLS implementation. Instead it uses whatever the Android version it is running on provides.

You can check here which TLS versions and (probably more important) ciphers your Android version supports: SSLSocket.

To map Android version numbers to their API level values, see SDK Platform release notes.

Yes, I meant TLS. Fat fingers, little keyboard.
When I go into settings for K9 I only get 2 choices for security protocols, 1.0 or 2.0., where I’m polling from, says they can no longer accept protocols of 2.0 or below. How can I get K9 to work with

TLS 2.0 still sounds wrong. Could you please post the exact error message you are seeing? When do you get that error message? When adding an account?

Where in K-9 are you getting an option to choose between different TLS/SSL versions?

1 Like

According to’s FAQ, they are dropping TLS 1.0 and 1.1. This still leaves you with TLS 1.2 and TLS 1.3.

For some strange reason, they still support SSL 3. Or at least, I am unable to find a hint that they discontinued to support it. Their manuals even still suggest a choice of SSL or TLS for fetching mails and no encryption for sending…