I have a contact with the crypto setting "always encrypt" which consists of an email address and a first name. Now I recieved an email from someone who also has just his first name in the from address. And it is the same name. I replied to this email. The bug is that KMail applies the crypto settings of a different person to this email. It encrypts the email with the key of someone else. If I try to prevent that in the "these keys are going to be used" dialog then I have to create an address book entry. If I don't do that then the email is sent encryptedly. If the second person has its own address book entry then this problem does not occur. To make it worse: I just deleted the address book entry for the second address and replied to the email again (for testing). This time the email was sent unencryptedly (the key dialog did not appear either). Reproducible: Sometimes
This bug has only been reported for versions before 4.14, which have been unsupported for at least two years now. Can anyone tell if this bug still present? If noone confirms this bug for a Framework-based version of kmail2 (version 5.0 or later, as part of KDE Applications 15.12 or later), it gets closed in about three months.
Just as announced in my last comment, I close this bug. If you encounter it again in a recent version (at least 5.0 aka 15.08), please open a new one unless it already exists. Thank you for all your input.