I am setting up k9mail on a 4.2 device (rooted Sony Xperia Mini Pro with stock ROM and crap removed) and it complains about the IMAP SSL certificate not being valid.
This happens with both a self-signed certificate, and also on a different IMAP server with Comodo-signed certificate (which is normally accepted by browsers and other mail clients).
Unrecognized Certificate
The server presented an invalid SSL certificate. Sometimes, this is because of server misconfiguration. Sometimes it is because someone is trying to atta you or your mail server. If you you're not sure what to do, click Reject and contact the folks who manage your mail server.
(java.security.cert.CertPathValidatorException: Trust anchor for certification path not found.) Certificate chain[0]:
...
Clicking "Accept Key", however, make the same dialogue come up again and again in a loop.
What is the problem? Can it be that k9mail is unable to add the key to the cert store? How to debug this?