Postfix mailbox not exist from Internet

[mhagelstrom]

Hello,
I installed a few days ago a SMTP antispam server using postfix. My mail server is an exchange server and Im not using active directory.
My problem is the following I configured (at least I tried to) postfix to receive mails without checking if mailboxes really exist in Exchange.
These worked fine inside my network where I can telnet and send mails through my postfix and receive them correctly in the exchange. But when I try to do this from internet, I get an error saying that the mailbox doesn´t exist (550). I also tried to TELNET my box to the port 25 and I dont receive any answer (it connects but dont show any text).
Can somebody help me please??

Thanks in advance

Martin

[falko]

If you use Postfix' transports, then you don't have to create user accounts on the Postfix server. Something like this should work:

echo "smtp  *:[<IP address of Exchange server>]" >> /etc/postfix/transport
postmap /etc/postfix/transport
/etc/init.d/postfix restart

[mhagelstrom]

Actually. I did that, and thats why if I connect from inside my network using telnet, mails are sent successfully to the exchange box.
The problems is when the connection comes from Internet.
Any idea??

[falko]

What exactly is in your mail log when this happens?