unable to send email

addiss

New Email
Hi,
I've sbs, exchange 2003, and smtp relay...i'm able to receive email but not sending...port 25 is open on my firewall...please help
 

popowich

EQ Forum Admin
Staff member
Re: an able to send email

Hello,

Lets confirm that you can get out to the internet on port 25.

On the exchange server can you try:

Start -> run -> telnet 66.202.109.26 25

Are you able to reach port 25 on my mail server above?

Does it dead hang or do you get a 220 response from mail.emailquestions.com?

If you can't get out can you double check the exchange server? Sometimes anti-virus software such as McAfee will bock outbound port 25 by default until you allow it.

If you can connect to my mail server, but not relay e-mail, what do your logs say?

Are you trying to relay direct to the internet or are you trying to smarthost through your ISP's smtp relays or some other mail server?

-Raymond
 

addiss

New Email
Thanks for very fast reply...i'm really frastrated...
I've exchange server 2003 and another server for smtp relay....
My isp do not block port 25....
my router is linksys rv082...i did port (25)forward to my smtp relay server...
when i try to telnet your email server I've got "could not open connection to the host, on port 25: connect failed." I think the problem is on the router...yesterday i've spent 2hrs with linksys techsupports and they came up with nothing...they told me my setting is right...
What should I do now...
Thanks,
 

popowich

EQ Forum Admin
Staff member
Do you have any other computers on the network? If yes, can you do the same telnet to port 25 test in my first reply from those and see if they can connect? If they can get out then it shouldn't be a linksys problem.

If you don't have any other computers behind the Linksys can you hook up the exchange server direct to the internet for a few minutes?

If the exchange server still can not get out then it's not the linksys, or there is a small possibility that it's the linksys AND something else but that is not likely.

If the exchange server can get out with the linksys removed then you know to continue focusing on troubleshooting the linksys router.

Which anti-virus and firewall are you running on the exchange server?

Did you double check that it's not software on the exchange server blocking the outbound port 25?

-Raymond
 

addiss

New Email
I don't have any antivirus installed yet...i did telnet from another system behind the linksys and I've got the same result...if i telnet my email server from outside i can connect...
I'm not home right now, i don't have physical access to connect my server direct to the modem...is there any other way i can test or troubleshoote?

Thanks,
 

popowich

EQ Forum Admin
Staff member
You mentioned there is a second mail server for smtp relay. Can you telnet to port 25 on that server from the exchange server to confirm the exchange server itself is not the problem?

Multiple computers having the same problem and no anti-virus installed reasonably narrows the problem down to a network problem. Have you confirmed with your ISP that they do not block outbound port 25? Some ISP's only block outbound port 25 but do not block inbound which could be why you are receiving but not able to send e-mail. I'd double check this before spending too much time banging you head against the linksys.

If it's not your ISP blocking outbound port 25, then yes, I'd say you are correct in figuring that the linksys is the problem. I'm not sure how close the config menus are between your linksys and mine. At home I have a Linksys BEFVP41 VPN router. In it's default mode I have no problem sending out e-mail. I'd have to create access specific rules it looks like to block the outbound port 25.

Is this a production environment? If all else fails, do you have the ability to upgrade or reinstall the latest firmware for the linksys, and start the configs from scratch? See if outbound smtp works, and if so start adding your rules 1 by 1 until the problem reoccurs so you know which part of the config needs to be fixed?

-Raymond
 

addiss

New Email
I've talk to my ISP provider and do not block port 25...
I telneted from my exchange server to my smtp relay server and i'm connected.
I've the latest firmware on my router...i may be reset it and configured it from scratch... I'll let you know the result.
Thanks,
 

addiss

New Email
Hi Popwich,
I really need your help here ....
The router is not the problem. I tried it with out router and firewall.. am still not able to send out email, i couldn't even able to telnet your mail server and am still able to receive... I really don't know what to .
i really appreciate your help very much.
 

popowich

EQ Forum Admin
Staff member
Hello,

Have you triple checked that your ISP allows OUTGOING port 25? :)

Can you get out on other ports, for example port 80 (http)?

Which ISP is providing your internet connection?

Can you list all the pieces of your connection from top to bottom?

For example:

  • The Name of the ISP who provides the internet connection
  • ISP DSL box
  • Linksys Router
  • Exchange server
What is the IP address for the linksys given to you by your ISP?

Is it a DHCP or statically assigned IP address?

What is your default router on the exchange server?

What routes are on the exchange sever?

You can get this info by opening up a command window and typing "route print"

start -> run -> command

in the box:

c:\route print

-Raymond
 

addiss

New Email
Hi Ray,

sending email worked for the couple days and in some reason stopped working...
-i don't know how to send using another port
-my ISP is teksavvy
.got sppedtouch dsl in bridge mode=>linksys RV082(192.168.200.253)=>smtp relay server (R2 2003)=>excahnge (SBS 2003 this server is also AD,dns and dhcp server) but my this 3 servers got static ip address...
-exchange default router is linksys(192.168.200.253).
here is the exchage server route print:-

IPv4 Route Table
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x10003 ...00 06 5b fd 9d 5a ...... Intel(R) PRO/1000 XT Network Connection
===========================================================================
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.200.253 192.168.200.1 10
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.200.0 255.255.255.0 192.168.200.1 192.168.200.1 10
192.168.200.1 255.255.255.255 127.0.0.1 127.0.0.1 10
192.168.200.255 255.255.255.255 192.168.200.1 192.168.200.1 10
224.0.0.0 240.0.0.0 192.168.200.1 192.168.200.1 10
255.255.255.255 255.255.255.255 192.168.200.1 192.168.200.1 1
Default Gateway: 192.168.200.253
===========================================================================
Persistent Routes:
None


and My smtp route print is:-

IPv4 Route Table
===========================================================================
Interface List
0x1 ........................... MS TCP Loopback interface
0x10003 ...00 11 43 b0 f3 52 ...... Broadcom NetXtreme 57xx Gigabit Controller
===========================================================================
===========================================================================
Active Routes:
Network Destination Netmask Gateway Interface Metric
0.0.0.0 0.0.0.0 192.168.200.253 192.168.200.10 20
127.0.0.0 255.0.0.0 127.0.0.1 127.0.0.1 1
192.168.200.0 255.255.255.0 192.168.200.10 192.168.200.10 20
192.168.200.10 255.255.255.255 127.0.0.1 127.0.0.1 20
192.168.200.255 255.255.255.255 192.168.200.10 192.168.200.10 20
224.0.0.0 240.0.0.0 192.168.200.10 192.168.200.10 20
255.255.255.255 255.255.255.255 192.168.200.10 192.168.200.10 1
Default Gateway: 192.168.200.253
===========================================================================
Persistent Routes:
None
Thanks,
 

popowich

EQ Forum Admin
Staff member
Does the exchange server have working DNS resolvers listed?

If you use smtp.teksavvy.com as a smarthost can the exchange server send e-mail?

-Raymond
 

yukon

Valued Member
Popowich:

let's back up for a moment and regroup:

addiss:
I have skimmed through the previous posts in this thread and at the request of a friend am adding my two cents, please bare with me while I get caught up as a couple of your posts were a little unclear:

1. have you been able to connect on port 25 to any external SMTP relay? (on both the affected mail server and another host within your network (like a laptop or desktop). For this test use Ray's previously provided SMTP IP (telnet 66.202.109.26 25 and probably best to use someone else's too, such as gmail-smtp-in.l.google.com (do a DIG for MX of gmail.com .... http://dig.menandmice.com/knowledgehub/tools/dig)

2. depending on the above results we can most likely eliminate your exchange server completely from the problem. It sounds like you did this before and were unsuccessful which points to only two last components, either your ISP or your router. Depending on your circuit (dsl, cable, T1, fiber, etc.) the router may or may not be the next easiest thing to eliminate. It sounds like you're probably on either DSL or Cable if you're using a LinkSys. Simply take the ethernet cable going into the WAN port on your router and move it to a PC, most preferably a spare laptop would be easiest. (obviously make sure double, triple check that the wireless connectivity is turned off if you're using a laptop or any system with wireless.) Next re-attempt the steps in step 1.

From what I've read so far you have not yet been able to successfully build an OUTGOING SMTP connection from your network either with or without your LinkSys router in place, which clearly leaves only your ISP to blame, regardless of how tech savy they seem to be or what they have informed you over the phone. Please take the extra 10 minutes and complete my excersize in steps 1 and 2. Even if you think its an effort in futility it will at least give you ammunition for your ISP when you call them back and re-accuse them of being the problem.
 

addiss

New Email
am not able to send email using teksavvy smart host...and i don't know how to check if Exchange uses DNS resolver...Exchange and DNS are on the same server.
 
Last edited:

yukon

Valued Member
since exchange 2003 it appears Exchange no longer has a separate DNS resolver configuration for OS and SMTP (used to have to configure it on both the NIC and again within the Exchange settings)

How to Configure DNS Settings on the Exchange Server

apparently it now inherits whatever config you put on your NIC.

also:
Addiss - what about my previous post, did you have a chance complete my instructions?
 

addiss

New Email
I've been waiting for reply from my isp and told me that they manually blocked port 25... they said y system might infected...thank for your help...i've one more question though, what anti virus and anti spam you suggesting me?
 

popowich

EQ Forum Admin
Staff member
I'm glad we have that figured out. Did they unblock port 25 for you yet?

In addition to anti-virus and spam filtering you also need to check that you are not vulnerable to backscatter. Make sure that you are 5xx rejecting e-mail to invalid recipients before you accept it. It's not as good of a solution but you can also fix a backscatter problem by disabling NDR's in Microsoft exchange.

Do you have a budget for your mail servers? At my work I run qmail servers that handle the anti-virus, spam filtering, and RBL checks and then hand off any good e-mail to the internal exchange servers. The internet can not make any connections directly to the exchange servers. I'm a unix guy and use ClamAV for anti-virus and SpamAssassin for content filtering in addition to several RBL's and some other checks. A good RBL to enable on your mail server is zen.spamhaus.org.

For exchange, since you are likely in a corporate environment, you'll probably want to get licensed versions of McAfee for the exchange server. For the spam filtering GFI Mail Essentials seems to have some good reviews and is priced cheaper than several other solutions it is compared to. Yukon may have some better ideas for the Windows mail server world.

-Raymond
 
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