[PLESK] Enable incoming mail service on port 26

Enable another port, i.e port 26 for qmail

# vi /etc/services
Add :
--
smtp_in         26/tcp          mail_in         #signetique incoming mail without rblDNS
smtp_in         26/udp          mail_in         #signetique incoming mail without rblDNS
--
# vi /etc/xinetd.d/smtp_in
---
#ATTENTION!
#
#DO NOT MODIFY OR DELETE THIS FILE, CREATED BY JOHAN
service smtp_in
{
   socket_type     = stream
   protocol        = tcp
   wait            = no
   disable      = no
   user            = root
   flags      = IPv6
   instances       = UNLIMITED
   env             = SMTPAUTH=1
   server          = /var/qmail/bin/tcp-env
   server_args     = -Rt0 /var/qmail/bin/relaylock /var/qmail/bin/qmail-smtpd /var/qmail/bin/smtp_auth /var/qmail/bin/true /var/qmail/bin/cmd5checkpw /var/qmail/bin/true
}
---

Reload xinet.d service :

/etc/init.d/xinetd reload