To impede spam (unsolicited bulk mail) on the Internet, ISPs (Internet Service Providers), including Toronto Free-Net, impose restrictions on the flow of email. Some checks are defensive, which an ISP imposes on inbound email to protect itself; others are self-policing, which an ISP imposes on email sent by its own users, to prevent them from abusing the Internet community at large.
If TFN rejects your legitimate email to addresses @torfree.net please compare, against the following possible causes, the error message which TFN gave to your SMTP server. For further assistance in resolving the problem, contact the TFN office.
When your outbound email server initiates the SMTP conversation to TFN's MX, by what name does it identify itself in the HELO/EHLO verb? There must be a DNS A resource record for that name, and that record must specify the IP address actually used by your SMTP server when it connects to us.
There must be a reverse DNS entry for your outbound SMTP server's IP address. The domain name specified by that PTR resource record must match an A record which, in turn, must resolve back to the IP address from which your SMTP server is connecting to us.
18/Jul/2011 update: TFN removed the reverse DNS requirement.
Your SMTP server's IP address and the name by which it identifies itself must not be blacklisted. TFN's SMTP servers check the following blacklists:
If you have been blacklisted, please address the cause, then follow the blacklist's instructions to request that your name be cleared.