Delete email user unknown error

[joximu]

small correction

1) remove from ipspcp database (table mail_users)
2) remove from postfix config (/etc/postfix/ispcp/aliases, mailboxes and senderaccess), postmap them and don't forget the working copy of theese files!
3) also remove the user manually from the courier userdb and the sasldb
4) remove the files+folders in /var/mail/virtual/domain/mailaccount

/J