How to change the address Qmail send error message (MAILER-DAEMON@hostname)

Plesk administrator's email address is listed in the following files: (By default)
/var/qmail/alias/.qmail-mailer-daemon
/var/qmail/alias/.qmail-postmaster
/var/qmail/alias/.qmail-root


Edit the above files and set the email which you need. The qmail error message of the form MAILER
-DAEMON@hostname will be send to that email id.

Zip Files being Blocked (Qmail)

Check whether the signatures file existing in the /var/qmail/control/. If this file existing then
check whether any statements in that file.

If there is any content, do the following:
vi /var/qmail/control/signatures
quick easy search and replace with vi using the following (Commenting the line in signatures file
):
%s/^/#/

Save and restart qmail it will work fine.