Version: 1.7 (using KDE KDE 3.3.0) Installed from: Compiled From Sources Compiler: gcc 2.95.3 OS: Linux When attempting to send an email to a local user (the 'To' address being simply the user's login name, without domain) via the sendMessage() DCOP call, the DCOP call returns with a success error code but KMail displays "You must specify at least one receiver, either in the To: field or as CC or as BCC." If I compose an email manually in KMail and enter the same 'To' address (i.e. just the user login name), the mail gets sent successfully. Also, sending the mail using just the user's login name works directly through sendmail.
As far as I can tell from the kmail code this is by design. I'm not sure this is documented anywhere but I'm pretty sure the DBus reply doesn't indicate if the mail has been sent successfully. I agree it's something really useful though. Maybe this should be made a wish.
KDE4 doesn't use DCOP.