When creating an encrypted mail to user@mydomain.com, I get a message that 'the identity chosen does not have a key to send an encrypted mail to yourself' (Sie haben angegeben, dass Nachrichten verschlüsselt an Sie selbst verschickt werden, aber die gerade ausgewählte Identität legt keinen (OpenPGP oder S/MIME) Schlüssel hierfür fest. Bitte legen Sie den Schlüssel für diese Identität fest.)
In the setup dialog for encryption, my key is not accepted. This is strange, as I can reply to an encrypted mail from user@mydomain.com and do not get this error message. Did not have this problem in KMail1 at all.
Finally, it is unclear what the source for the problem really is....(no help available)

Reproducible: Always

Steps to Reproduce:
1. create mail and hit 'encrypt'
2. message about missing key
3. Own key is not accepted
4. Message is sent unencrypted!
Actual Results:  
unecrypted message sent, not possible to enter 'own key'

Expected Results:  
sent encrypted message

KDE 4.8.2 
Feel free to send me an encrypted message to test