Version: 1.9.3 (using KDE 3.5.3, compiled sources) Compiler: gcc version 3.4.5 OS: Linux (i686) release 2.6.16.20 I changed one name of accounts->send profile in KMail settings to another name. Later when I tried to send something the e-mail was sticking in outbox without reporting any error. When several times tried to send this message sometimes got "unknown protocol message". The smtp server was always working OK because on the same machine I could send the same message using another mail client (mozilla seamonkey mail client). How to fix: Go to KMail settings->Identitiy-> <profile name> -> advanced->Send field name and change old name to new name. Check all Identity profiles' send field for old name and change it to new one. Conclusion: When user changes send profile name in accounts, KMail should scan all Identity profiles for old name in Send field and update this field with new name.
Cannot confirm in KDE 4.3. If you can still reproduce this, I didn't understand you and did something wrong