In article <[🔎] 20081223203134.GH28542@tamay-dogan.net> you wrote:
From: popcon@tp570.private.xxxxx-xxxxx.net
which is probably correct and since I am sending THIS message over the
same relay <mail.private.tamay-dogan.net> I know, my Mailserver is
working.
You could try to set a different official sender address without the
internal domain.
It seems, courier-mta is trying to deliver the messages several hours
without success and then it is working, but I do not know...
I dont know about courier, with exim i can easyly see the delivery to my
upstream relay. If it takes longer for your gateway to deliver it, you
should see an error message?