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SMTP Relay

Patrick

SMTP Relay
« on: June 26, 2003, 05:47:29 PM »
I have a question regarding E-smith 5.5. We have installed E-smith and are using it as an firewall. We us a MS Exchange 2000 server for all e-mail.

 

At first we had an open relay issue, where our exchange server was being used to send spam. I have put up restrictions on relay in MS exchange and the server is no longer an open relay, the only problem that occurred after applying these restricitions is that when a user replies to an e-mail they receive the following error:

 

Your message did not reach some or all of the intended recipients.

 

      Subject:  FW: xxxxxxxx

      Sent:      6/23/2003 2:20 PM

 

The following recipient(s) could not be reached:

 

      'xxxxxxx@xxxxxxx.com' on 6/23/2003 2:20 PM

            You do not have permission to send to this recipient.  For assistance, contact your system administrator.

           

 

According to Microsoft this issue can occur if the Auth and Auth login commands (Extended Simple Mail Transfer Protocol [SMTP] commands) are stripped by a firewall/router.

 

Could someone tell me how to correct this issue ?

Nathan Fowler

Re: SMTP Relay
« Reply #1 on: June 27, 2003, 05:47:55 AM »
If your Exchange box sits behind the router, and your internal users are replying to messages and getting this error, then port-forwarding/filtering from the SME box wouldn't be applicable, since those packets intended for the Exchange server aren't routed though the SME box.

I think you were too restrictive when setting up your Exchange box, and as both an Exchange 5.5/2000 administrator and a qmail administrator, let me say this:  Exchange sucks.  Exchange 5.5 is garbage, and Exchange 2000 is riddled with bugs and security concerns.

Why not just use the SME mail server, which is much more useful, and impressively less expensive ;)

Rob Delissen

Re: SMTP Relay
« Reply #2 on: June 28, 2003, 04:14:53 PM »
I'm concerned about the security of Exchange as well. So I placed an e-smith server in front, to collect mail from the internet, and pass it on to Exchange, as delegate. Outgoing mail goes the same way. E-smith also checks on virus and spam before letting it into the network. Works like a charm.

Rob Delissen

Re: SMTP Relay
« Reply #3 on: June 28, 2003, 04:14:54 PM »
I'm concerned about the security of Exchange as well. So I placed an e-smith server in front, to collect mail from the internet, and pass it on to Exchange, as delegate. Outgoing mail goes the same way. E-smith also checks on virus and spam before letting it into the network. Works like a charm.

Rob Delissen

Re: SMTP Relay
« Reply #4 on: June 28, 2003, 04:14:55 PM »
I'm concerned about the security of Exchange as well. So I placed an e-smith server in front, to collect mail from the internet, and pass it on to Exchange, as delegate. Outgoing mail goes the same way. E-smith also checks on virus and spam before letting it into the network. Works like a charm.