Version: 1.9.51 (using 4.00.80 (KDE 4.0.80 >= (KDE 4.1 Beta1), Debian packages) Compiler: cc OS: Linux (x86_64) release 2.6.25-melech It happens regularly that Kmail mysteriously terminates, apparently without crashing. I only notice that the tray icon disappears, and that the kmail process is no longer running. I think this happens mostly when there is a network connection error, such as when the laptop is brought back from suspend and old connections go down. I'm using two IMAP accounts with TLS. I attached gdb to the kmail process. After a while the bug was triggered, but gdb just said "Program exited normally." Of course I didn't request it to close.
It happened again, immediately after dismissing the dialog box about connection error.
Which qt version do you have?
Debian 4.4.0-2.
*** This bug has been marked as a duplicate of 163479 ***