[Mimedefang] Too many files open

[Trevor]

Hi,
 
I have two Solaris servers one running Solaris 8 and the other Solaris 10.
Recently they both have been logging the following:
I've added ulimit -n 1024 even tried 2048,  I also added set
rlim_fd_max=4096, set rlim_fd_cur=1024 into /etc/system none of this seems
to help.
This error just started. It's causing major problems as I have to restart
mimedefang and sendmail around 8 times a day.
I'm running mimedefang 2.56 with spamassassin 3.1.1, I have limited
sendmail's child processes to 500.
Each server averages around 80 000 emails a day.
 
Apr  4 16:48:14 mx1.johncom.co.za mimedefang[28850]: [ID 384225
mail.warning] k34Elkgo013197: Could not open
/var/spool/MIMEDefang/mdefang-k34Elkgo013197/COMMANDS: Too many open files
Apr  4 16:48:14 mx1.johncom.co.za sendmail[13197]: [ID 801593 mail.info]
k34Elkgo013197: Milter: from=<xxxx.xxt at xxxa.net>, reject=451 4.3.2 Please
try again later

Apr  4 14:46:58 mx1.johncom.co.za mimedefang[12497]: [ID 384225
mail.warning] k34Ckwx4027216: Could not open
/var/spool/MIMEDefang/mdefang-k34Ckwx4027216/INPUTMSG: Too many open files
Apr  4 14:46:58 mx1.johncom.co.za sendmail[27216]: [ID 801593 mail.info]
k34Ckwx4027216: Milter: data, reject=451 4.3.2 Please try again later

Any help on this matter would be appreciated.

Thanks
Trevor