I've just done a test with K9 mail on Android 4.4.2 and this is what I see in the log: ECDHE-ECDSA-AES128-SHA (128/128 bits) But when using Thunderbird I see: ECDHE-ECDSA-AES128-GCM-SHA256 (128/128 bits) I'm happy that Thunderbird is using a secure cipher but is Android? Is ECDHE-ECDSA-AES128-SHA ok/secure?