I've set up postfix so that it directs mails with a specific address as the recipient (namely <number>@fax.mydomain) to a hylafax mail-to-fax gateway. This has been done with an entry in the transport database.
Now I need it to send all other e-mails to another server, an exchange server, since I cannot get past the firewall with my linux box. So in the current installation, if I send an e-mail within the intranet, it gets delivered. But if I want to send it out, my postfix cannot deliver the mail.
relayhost = myexchangeserver
but apparently now I don't get any mails delivered, even if they are only in the intranet.
Is the relayhost the right setting to change? Or are there other things I've missed?