tcp_do_segment....again

Hi guys.

I post a question few days ago.

this is the link :

http://groups.google.com/group/mailing.freebsd.current/browse_thread/thread/de0953974d6dd9f4/f35d27cbe374b799?show_docid=f35d27cbe374b799&fwc=1

I was reading this post :

http://unix.derkeiler.com/Mailing-Lists/FreeBSD/current/2007-08/msg00174.html

and this :

http://unix.derkeiler.com/Mailing-Lists/FreeBSD/net/2008-04/msg00047.html

The problem persist even in stable 7.0, 7.1-PRERELEASE and 7.0-P5 ,  
the postfix jail is living all the email in defer queue saying  
"Connection Time Out"

This server give service to 300 clients and the network load os high.

is there any clue how to resolve this ?

Thanks.