Version:           1.13.0 (using 4.3.90 (KDE 4.3.90 (KDE 4.4 RC1)) "release 212", KDE:KDE4:Factory:Desktop / openSUSE_11.2)
Compiler:          gcc
OS:                Linux (i686) release 2.6.31.8-0.1-desktop

Whenever I select a mail, a new dbus-daemon file descriptor is being used, but not closed when I select a different mail.

I first discovered this problem, when I tried to use kmail after it was running for some time and dbus-daemon needed 100%CPU and I could no longer do anything useful with KDE.

Now, when I do
ls -1 /proc/6813/fd | wc -l
where 6813 is 
/bin/dbus-daemon --fork --print-pid 5 --print-address 7 --session
and I select a different mail (local inbox from my POP account),
and do the counting again, it increases by one - until
it reaches 1024 where then everything stops working correctly.

If the mail is plain text or HTML does not matter. The mails are also not signed.

I assume it has something to do with akonadi or nepomuk, because I did never experience this before I installed 4.4 RC1 (before I used 4.3.4).

I have only kmail running, no other PIM application.

I had now 129 open file descriptors, then I stopped akonadi (akonadictl stop) and the number dropped to 40.
Now I can no longer select any mail as clicking on a new mail hangs kmail (I think I read about getting the mailer address via akonadi, which won't work now)

Starting now akonadi again crashes kmail... OK, I'll open another bug issue.