> Finally it's working!. > You where right. There was something interfering. > Turns out that our cisco firewall had some smtp fix-up feature > enabled. After disabling it i could telnet smtp from the outside as i > did from the inside.
cisco pix? FYI Question Background: I have a Cisco PIX firewall in place. I am trying to force SMTP authentication so that remote users can relay through my server without having to open my server up to true relay. The problem is, no one outside my firewall can use SMTPAuth. Why is this? Answer: This likely because your firewall is using the SMTP Fixup protocol. This is stopping the EHLO command sent by the clients being passed on to the server. As the EHLO command is rejected the clients then correctly go on to use HELO and thus can not authenticate. Disable fixup on your router and the clients will then be able to send the EHLO Command correctly. If your firewall is a Cisco PIX then you should be able to use the command: no fixup protocol smtp 25
