Too many Close_wait 0n port 25

Folks,

I am running Netscape messaging Server 4.15Patch 4 ON Solaris 5.6.I am kind of running into a wiered problem once a week as my smtpd daemon hangs

when i see netstat -a |grep 25 ,I see lot Close_Wait state.I ahve treid modifying all the settings realted to tcp stack,but all in vain.

I need Physically hard boot the system for it to send out mails.

Any solution or help would be appreciated.

[435 byte] By [708756] at [2007-11-25 7:10:26]