To enable email piping of support tickets when using Plesk control panel you may need to use the following steps;
1. Create email address in plesk
2. Edit the file .qmail found in /var/qmail/mailnames/"domainname"/"address"
remove ./Maildir/ ( if you don't want the mail to be delivered into the mailbox )
add | preline /home/httpd/vhosts/"domainname"/httpdocs/"clientexecfolder"/SupportPipe.php"
3. Change permissions for SupporPipe.php to 755
This should get email piping working in plesk