Version: 1.13.5 (using KDE 4.6.2) OS: Linux KMail should have the capability of using signing subkeys in a complete way. Reproducible: Always Steps to Reproduce: If someone has a primary key that is used for signing and one or more subkeys also used for signing then KMail encounters gpg's default behavior in that when you select the key to use to sign, KMail/gpg automatically uses the last signing subkey rather than the primary (which is what it looks like it is doing when you choose what key to use). Actual Results: Your message is signed with your signing subkey rather than the primary signing key as you asked it to do. Expected Results: Sign the message with the primary key. OS: Linux (i686) release 2.6.35-28-generic Compiler: cc Kubuntu 10.10 GnuPG 1.4.10 GnuPG 2.0.14 libcrypt 1.4.5 Ideally there should be an option in emailidentities called force-exact-keyid=yes And there should be a corresponding checkbox in the GUI settings page somewhere. What this would do is append a ! to the end of the key fingerprint supplied in PGP Signing Key= This would force gpg to use the exact primary or subkey fingerprint supplied. Additionally the GUI interface would need to be changed in one additional way so that there are no gotchas: it would need to check the keyring for all possible valid signing key and subkeys and present this list to the user when they change the default signing key. At the moment all KMail presents the user with is a list of primary keys.
Thank you for taking the time to file a bug report. KMail2 was released in 2011, and the entire code base went through significant changes. We are currently in the process of porting to Qt5 and KF5. It is unlikely that these bugs are still valid in KMail2. We welcome you to try out KMail 2 with the KDE 4.14 release and give your feedback.