Yavuz,

Form the 557 error you described, it appears that the outlook client is connecting to SpamFilter, not to MailEnable, to send out its email. As SpamFilter by default will not emails to be relayed to a domain that is not in your local domains list, SpamFilter will reject the connectino with a 557 error.

You have several options available.

• Ensure your outlook client is using ME's IP of 123.123.123.124 as their "Outgoing SMTP Server". If you believe this is how the client is configured, make sure that SpamFilter and ME are not "fighting" to listen on port 25 on the server. By default SpamFilter will bind to port 25 on all IPs on the server. You can of course specify a single IP address to use, but you will need to do the same with ME. To verify which software is listening on port 25 of an IP, simply open a MSDOS prompt ant type "telnet 123.12.12.124 25". The welcome banner you receive should indicate that ME (and not SF) is listening on that IP.
• If you want the outlook client to use SpamFilter instead of ME as their "Outgoing SMTP Server", you will need to add the IP(s) of the client(s) to an IP whitelist in SpamFilter, so that they are allowed to relay.
• Implement SMTP Authentication in SpamFilter. We support Active Directory, LDAP, and Unix-style password files. Authenticated users are whitelisted and thus can relay emails anyhwere.
  

In regards to your issue, your ME web mail will usually always work as it interfaces directly with ME, and thus ME will always be able to send emails via that interface. Your outlook clients have a different configuration. They, as all other email clients, must use an "Outgoing SMTP Server" to send emails. Before implementing SpamFilter, your outlook clients were probably (we're simply guessing here, so I apologize if we guess wrong) using ME as their "Outgoing SMTP Server". When implementing SpamFilter, admins usually avoid changing their mail server (ME in your case) configuration, as if they were to change the port or the server name used by ME, that would require reconfiguring all the outlook clients.

If you decide to implement scenarion #2 of our network samples ("Single SMTP server with a single IP address directly connected to Internet"), that configuration requires changing the port of your ME server. Doing that would then also require all your outlook clients to change the port used in their "Outgoing SMTP Server" configuration, and is thus not an ideal solution.

We'd recommend using the first option, "SMTP servers directly connected to Internet". This allows you to keep "as-is" the ME configuration (and thus not requiring changes to your outlook clients). To do so however, you need to configure SpamFilter so that it listens on a different IP address than the one used by ME. This can be done, as you asked, from the "Settings - Confiiguration" tab in SpamFilter. Under the "SMTP listener socket" there is a blank entry for the "IP(s)". This indicates that SpamFilter will bind to port 25 on all IPs on the server. To configure SpamFilter to only listen on a specific IP address, simply enter that IP address in that field and click on "Save SMTP Settings". The final step in this configuration is to change your MX record to point to the new IP address used by SpamFilter rather than to the one used by ME. If your servers are behind a firewall, things are even easier, as at this point you can follow our sample #3 "SMTP servers behind Firewall", and instead of modifying your MX record, you can reconfigure your firewall to forward traffic to the IP used by SpamFilter rather than to ME.