Questions regarding overall setup.

[MasterTH]

1. after updating ispcp to a newer release you may have to do the steps again, because the installation & upgrade script just upgrade the default packages and configuration

2. the same problem could happen here.

3. i added a ssl-cert to my admin-page.

a) is good for antispam protection
b) which version of centos ur running? 32bit or 64bit? Take a look in ur log-files why the daemon is not running. the daemon runs the script when u add a user or delete one.
c) Antivirus Scanning Solution
d. another antispam-solution, wants the sender to resend the mail to activate the mail-adress. Otherwise the mail-adress is marked as spam-sender