In Settings => Configure KMail => Identities => Modify => Cryptography add an option to always attach the own public key by default. There are some reasons people might prefer to send their public keys by mail instead of publicly uploading them to keyservers. For those scenarios it's pretty useful to have an option, to always attach the own public key by default. Enigmail for Thunderbird provides a similar option. For this go to: (in Thunderbird) Enigmail => Preferences => Display Expert Settings and Menus => OK Account Settings => OpenPGP Security => Advanced => Attach my public key to messages Additionally KMail should name the attached key a little smarter. See https://bugs.kde.org/show_bug.cgi?id=353627 for details. Reproducible: Always