HowTos for users
Every user should change her or his password by using GOsa². To do so, just use a browser and go to https://www/gosa/.
Using GOsa² to change the password ensures that Kerberos (krbPrincipalKey), LDAP (userPassword) and Samba (sambaNTPassword and sambaLMPassword) passwords are the same.
Changing passwords using PAM is working (ie at the KDM/GDM login prompt), but this will only update the Kerberos password, and not the Samba and GOsa² (LDAP) password. So after you changed your password at the login prompt, you really should also change it using GOsa².
All users can send and receive mails within the internal network. To allow mail outside the internal network, the adminstrator needs to configure the mailserver exim4 to suit the local situation, starting with dpkg-reconfigure exim4-config.
Every user who wants to use KMail needs to configure it as follows.
Start KMail, click "Next" in the Account Wizard, select IMAP as account type, click "Next". Enter real name and e-mail address firstname.lastname@example.org, click "Next". Check if the username is correct, don't enter the password, click "Next". (Kerberos provides single sign on concerning SMTP and IMAP, so you don't have to enter your password.) Enter postoffice.intern twice as server name, click "Finish". Close the tip of the day. Click "Settings" in the KMail menu, select "Configure KMail...", then click on "Accounts". Click "Modify...", then "Continue" to accept the certificate problem and "Forever", "OK", "Apply" and once more "OK". That's it!
Now send a test email to yourself. (This will create the IMAP folders on the server.) Wait a little bit, then click "Check Mail" in the KMail menu. There should be your recently sent email in the inbox below of "intern".
Obtaining a Kerberos ticket to read email on diskless clients
If working on a diskless client, you don't have a Kerberos TGT by default. To get one, open up a terminal and execute kinit. Enter your password and the ticket will be granted.
On thin clients, pavucontrol or alsamixer (but not kmix) can be used to change audio volume.
On other machines (workstations, LTSP servers, and diskless workstations), kmix or alsamixer can be used.