my exchange server works fine, receiving and sending mail works as expected. now we want to use our barracuda spam firewall as we used it with our old linux mail server. after setting it up, receiving through the firewall works again, all mails get routed correctly. there's one single problem left, receiving:
on our old mailserver i just had to enter the url and the port as mailrelay, without authentication. so i did in my exchange sending connector and adjusted the sending port from 25 to 587 (as described in [1]) via the exchange shell.
the problem is, when i want to send a mail now, i get the following error mail back:
#550 message submission is for authorised users only! ##
this cannot be, because authentication is turned off and the linux server works anyway... as this wasn't clear: i want to send outbound mail through the barracuda!
Sender --> Barracuda --> Recipient
any advice on this issue?
thanks in advance!
[1] http://www.mharder.eu/exchange-2003-2007-2010-smarthost-smtp-port-umstellen/