RE: Can't telnet port 25 from server but can from other client

From: Michael Patrick (MichaelPatrick_at_discussions.microsoft.com)
Date: 12/16/04 

Date: Thu, 16 Dec 2004 14:23:02 -0800

Okay....lets try this....post your ipconfig /all Lets see where you sit on
that...
If you run the CEICW do you get a firewall config error? You may want to
try to run that and enter your ISP's mailserver....(I know again, entering it
 here rather in the smtp virtual server works better)

I am able to telnet into mainesource, so there isnt a problem there....

Do you have a router? I dont think I asked that one yet...oh wait, you did
say you have one with a dsl modem..... Not always is a router just for
incoming, it can block outgoing as well....so double check that connection as
well.

If this doesn't work hopefully some of the MVP's will take a look see on
this posting.... :)

"Julie Turner" wrote:

> All outgoing email is blocked. Neither smarthost or DNS work (i've tried
> both) but currently the configuration is using smarthost. I've tried 3
> different smarthost servers. To eliminate DNS from the equation I'm using
> the IP address of the smarthost and have verified they are responding to ping
> tests before trying them. I think if you boil the problem down a little
> deeper the problem is that I can't telnet on port 25 from the server to any
> SMTP server even one in the same network. If I turn SMTP services on on a
> client machine in the network I can't get to it etiher. But that client
> machine can telnet outside the network to a smtp server on port 25 which
> means my ISP isn't blocking port 25. It really seems like there is some sort
> of firewall or something that's blocking port 25 traffic out of the server,
> but I didn't turn the firewall on and there doesn't seem to be any way to
> tell if it's running "accidentily".
>
> "Michael Patrick" wrote:
>
> > Okay, restarted.....still nada....
> > Is it all outgoing e-mail that is getting stuck? Or just to a particular
> > domain?
> > And you didnt say if you are using a smarthost or dns to route e-mail...
> >
> > "Julie Turner" wrote:
> >
> > > Unfortunately starting and stopping the service did not do anything, although
> > > I was fairly sure it wouldn't becuase I've restarted the server several times
> > > today, and ran the internet and email connection wizard about 6 different
> > > times, hoping that something just want's "taking".
> > >
> > > As I said in my other email I know the ISP isn't blocking traffic on port 25
> > > for two reasons. The first, I called them and they said they don't. And the
> > > second, becuase if I go to another machine on the local network and try
> > > telnet smtp.mainesource.com 25 it connects. If I try to do the same thing
> > > from the server, it fails to connect, however, I can't ping
> > > smtp.mainesource.com and it responds so I'm fairly sure there is no DNS
> > > problem.
> > >
> > > The real pain here is that it was working at one point and isn't now for no
> > > apparent reason. There is a router and a DSL modem and they both have
> > > firewalls however, it's my understanding that firewalls such as these only
> > > block incomming traffic so I am not sure why I would want to open up port 25
> > > unless I'm just missing something there.
> > >
> > > "Michael Patrick" wrote:
> > >
> > > > Just for the heck of it......go to System Manager (exchange), under admin
> > > > groups, first admin, server, protocols, and then SMTP you have your virtual
> > > > server..... try to stop and restart.....
> > > >
> > > > If that doesnt work, we may want to check your settings there......or do you
> > > > have a router that might not be configured properly?
> > > >
> > > > Since you said it was working fine, and if restarting the SMTP server does
> > > > not help....call your isp and see if they changed anything recently....they
> > > > may have blocked your port 25 there..... Which this may be the case....
> > > >
> > > > Go to your SMTP Virtual server properties, delivery tab and advanced button
> > > > what is listed in smarthost?
> > > >
> > > > "Michael Patrick" wrote:
> > > >
> > > > > Running ISA at all?
> > > > >
> > > > > "Julie Turner" wrote:
> > > > >
> > > > > > Hopefully someone has some ideas...
> > > > > >
> > > > > > For about 3 weeks email has been happily coming in on the pop3 connector and
> > > > > > going out via forwarding to a smart host. Somehow something got changed and
> > > > > > all the sudden email is stuck in the SmallBusiness SMTP connector queue. I
> > > > > > cannot telnet to an external smtp server on port 25 from the SBS2003 server.
> > > > > > However, I can do so from another computer on the internal network which
> > > > > > disproves my original assumption that the ISP was blocking port 25.
> > > > > >
> > > > > > The Firewall on the server is turned off... or is the the best of my ability
> > > > > > to ascertain. However, it's been suggested to me that the server is blocking
> > > > > > outgoing traffic on that port. I've checked the TCP/IP filtering on the
> > > > > > network connection and none are set up...
> > > > > >
> > > > > > So at this point i'm at a loss. Anyone have any ideas?