Version: (using KDE 4.4.0) OS: Linux Installed from: Ubuntu Packages In KDE 4.4 Kmail composer the autocompletion of recipient email addresses still depends on old Kresources, while the new addressbook depends on Akonadi. After the migration of the old addressbook to the new "Personal Contacts" Akonadi resource, Kmail composer search for recipients' names matches still in the old resource. In my opinion this is a great security issue because, in the case a contact has changed email, it may mislead the sender, if he/she doesn't double-check the addresses.
A temporary workaround is to add the akonadi resource for contacts in kresources and to set it as the default address book. However this should be made automatically whenever a new akonadi address book is created, at least until kmail will be ported completely to akonadi.
*** Bug 191841 has been marked as a duplicate of this bug. ***
*** Bug 229125 has been marked as a duplicate of this bug. ***
This of course not only affects KMail, but all applications using the KResource API, e.g. Kopete, Konversation etc etc
I also can confirm this issue in KDE SC 4.4.1
*** Bug 216100 has been marked as a duplicate of this bug. ***
Fixed, Tobias and Casey ported the address completion to use native Akonadi API.