A client of mine has a Red Hat box (7.3 from memory) running qmail as there email server. Things have been working fine up until the last few months.

There are some email addresses that mail doesn't get through on. After a week or two the client recieves a "failure notice" back with the following information:

Connected to *.*.*.* but the connection died. (#4.4.2)
I'm not going to try again; this message has been in the queue too long.
The first thing I did was to enter there ISP's SMTP server into the /var/qmail/control/smtproutes file.

and restarted the qmail service using "service qmail restart"

But they are still having the same problems. Is there anyway to confirm that the mail is being forwarded to the ISP's mail server and not being delivered directly? or should I reboot the server for that setting to take effect?

Thanks in advance,