Creating tickets for my mails

Dear all,

I installed a request tracker on a FreeBSD system. The request tracker is working well but I have problem injecting my administative mails into it. When i tried to send email into the request tracker, sendmail returns this error:
404 Not Found
“|/usr/local/rt3/bin/rt-mailgate --queue support --action correspond --url”… Deferred: prog mailer (/bin/sh) exited with EX_TEMPFAIL

On the Request Tracker Server, I created a testfile and did a ‘cat testfile |/usr/local/rt3/bin/rt-mailgate --queue support --action correspond --url’ (with this I expect the content of the testfile to be created as a ticket on the request tracker)
I got this error:
500 Can’t connect to (connect:Invalid argument)

Does any one has a clue to what the problem is?