Yet another relay problem.

Yet another relay problem.

Post by Tyle » Sat, 13 Apr 2002 14:58:54



Hi all,

Our mail server is an open relay. Every time I try to prevent relaying
I also prevent all of the email clients on the LAN from sending email.
 Our email server is a NT 4.0SP6 box running Exchange 5.5 SP4.

The 'Hosts and clients with these IP addresses' routing restriction is
causing me grief.  In order to prevent relaying I need to check this
checkbox.  However, checking this checkbox also prevents all of the
email clients on the LAN from sending email. At first I checked the
'Hosts and clients with these IP addresses' checkbox and left the list
of IP addresses empty.  Although this prevented relaying it also
prevented email clients on the LAN from sending email.  Then I checked
this checkbox and built a list of local IP addresses, but sadly met
with the same result.  The only alternative seems to be an open relay,
which is really evil.

In search of some insight I telnetted to our email server on port 25.
I tried to send an email to myself, but the email server rejected me.

220 ESMTP spoken here
helo me
250 xxxx.xxxxxxx.xxx Hello [192.168.1.199]
mail from: xxxxxx.xxxxxxx.xxx
250 xxxxxx.xxxxxxx.xxx....Sender OK
rcpt to: xxxxxx.xxxxxxx.xxx
550 Unable to relay for xxxxxx.xxxxxxx.xxx

I thought that email clients on the LAN would be unaffected by mail
relay settings. Therefore I thought that I would be able to send an
email to myself, but I was unable.  I read the article 'Is Your
Exchange Server Relay Secure?' and various technet articles but they
didn't give me any further insight. I'm confused, and any help would
really be appreciated.

Cheers.

 
 
 

Yet another relay problem.

Post by AI » Sat, 13 Apr 2002 15:25:18


Hello,

Didn't you try "Hosts and clients that successfully authenticate" option?
Please refer to http://www.slipstick.com/exs/relay.htm and
http://www.exchangeadmin.com/Articles/Index.cfm?ArticleID=7696 for useful
information.

Regards,
Intermedia.NET (AI)
Microsoft Certified Solutions Provider
Providing expertise in hosting applications
MS Exchange Hosting: http://www.intermedia.net/exchangehosting
Windows 2000 Web Hosting:  http://www.intermedia.net/webhosting
For a waiver of the set up fee use "IMFREE" code


Quote:> Hi all,

> Our mail server is an open relay. Every time I try to prevent relaying
> I also prevent all of the email clients on the LAN from sending email.
>  Our email server is a NT 4.0SP6 box running Exchange 5.5 SP4.

> The 'Hosts and clients with these IP addresses' routing restriction is
> causing me grief.  In order to prevent relaying I need to check this
> checkbox.  However, checking this checkbox also prevents all of the
> email clients on the LAN from sending email. At first I checked the
> 'Hosts and clients with these IP addresses' checkbox and left the list
> of IP addresses empty.  Although this prevented relaying it also
> prevented email clients on the LAN from sending email.  Then I checked
> this checkbox and built a list of local IP addresses, but sadly met
> with the same result.  The only alternative seems to be an open relay,
> which is really evil.

> In search of some insight I telnetted to our email server on port 25.
> I tried to send an email to myself, but the email server rejected me.

> 220 ESMTP spoken here
> helo me
> 250 xxxx.xxxxxxx.xxx Hello [192.168.1.199]
> mail from: xxxxxx.xxxxxxx.xxx
> 250 xxxxxx.xxxxxxx.xxx....Sender OK
> rcpt to: xxxxxx.xxxxxxx.xxx
> 550 Unable to relay for xxxxxx.xxxxxxx.xxx

> I thought that email clients on the LAN would be unaffected by mail
> relay settings. Therefore I thought that I would be able to send an
> email to myself, but I was unable.  I read the article 'Is Your
> Exchange Server Relay Secure?' and various technet articles but they
> didn't give me any further insight. I'm confused, and any help would
> really be appreciated.

> Cheers.


 
 
 

1. Yet another relay question

Exchange Server 5.0 is being used as relay. I have not seen any articles on
technet or this newsgoup that discuss potential ways to stop this. I can,
for the time being, restrict the "relaying" user via our firewall.

Is there any way within Exchange 5.0 to stop relaying?

We will be upgrading to Exchange 5.5 soon, but till then???

2. WEB EXCHANGE ACCESS

3. Yet another SMTP relay question...

4. How to detect whether server is Exchange 5.5 programmatically

5. Yet another Outook Web access problem - all people with these problems please read this (long)

6. Exchange Server behind firewall

7. Wierd problem - Microsoft yet to help...

8. exchange 2000 behind isa

9. MTA Logs Errors in event yet no problems

10. Wierd problem - Microsoft yet to help...

11. Yet another problem

12. Yet another Event Sink registration problem