tcp-env lot of connections

[trec]

I am having a lot of connections on tcp-env they are from the smtp users sending e-mail on the server, the problem is they still remain open on the server and then the server stop accepting new smtp processes.

here is the list of processes of this kind: (have to remove half of the lines for posting purposes)

root 19529 0.0 0.0 1612 484 ? S 11:17 0:00 tcp-env -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
root 19620 0.0 0.0 1592 480 ? S 11:17 0:00 tcp-env -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
root 19703 0.0 0.0 1604 480 ? S 11:17 0:00 tcp-env -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
root 19776 0.0 0.0 1608 480 ? S 11:17 0:00 tcp-env -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
root 19845 0.0 0.0 1596 480 ? S 11:17 0:00 tcp-env -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
root 19895 0.0 0.0 1596 480 ? S 11:17 0:00 tcp-env -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
root 19910 0.0 0.0 1604 484 ? S 11:17 0:00 tcp-env -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
root 19957 0.0 0.0 1600 484 ? S 11:17 0:00 tcp-env -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
root 20132 0.0 0.0 1592 484 ? S 11:18 0:00 tcp-env -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
root 20136 0.0 0.0 1604 480 ? S 11:18 0:00 tcp-env -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
root 1226 0.0 0.0 1600 476 ? S 11:25 0:00 tcp-env -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
root 1235 0.0 0.0 1604 476 ? S 11:25 0:00 tcp-env -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
root 1245 0.0 0.0 1596 476 ? S 11:25 0:00 tcp-env -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
root 1259 0.0 0.0 1592 476 ? S 11:25 0:00 tcp-env -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
root 1348 0.0 0.0 1600 476 ? S 11:25 0:00 tcp-env -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
root 1349 0.0 0.0 1608 476 ? S 11:25 0:00 tcp-env -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
root 1435 0.0 0.0 1604 476 ? S 11:26 0:00 tcp-env -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
root 1464 0.0 0.0 1600 476 ? S 11:26 0:00 tcp-env -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
root 1475 0.0 0.0 1608 476 ? S 11:26 0:00 tcp-env -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
root 1653 0.0 0.0 1592 472 ? S 11:26 0:00 tcp-env -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
root 1661 0.0 0.0 1600 472 ? S 11:26 0:00 tcp-env -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

right now I can only fixi it killing all the tcp-env processes, but this not happens on my other servers, any clue?
using Plesk 7.5.4 RHES