ukoda writes: Given the GMail Android app is bundled with most Android phone and has offered support for email accounts with other service providers it has become a popular email client. However sometime in November last year Google updated their app to silently reject self-signed certificates. For users of servers with self-signed certificates their email stopped coming in. Refreshing the inbox appears to go normally with no problems reported. From this support thread it is apparent that server connections are being rejected with the warning "Certificate Not Valid" even when the "All Certificates" option is chosen. The explanation from Google is they are improving security but for some users that had a working secure connection they now have to either stay with GMail, and turn off encryption, or move to a new app such as K9 or BlueMail. The lack of meaningful responses from Google leave little hope of things improving anytime soon.