SMTP Issues sending outside mail

[dvannoy]

Question,

2003 exchange running basic configuration. Cisco ASA setup correct to allow SMTP through the firewall.

I have a web application inside my network that will send email notifications out to users using SMTP. Now, most of the time ,not all the time the email never makes it to the external user. users inside my network ALWAYS get the emails sent. is there something I should be looking at here? did I miss something wheile setting up the exchange server?

any help would be appreciated

Thanks

 

[danielwestendorf]

Start by eliminating your web app from the equation to see if the problem is with exchange at all.

Can you send an email through your Exchange server to an external recipient via telnet? Through an SMTP client? This will tell you if Exchange is delivering to external addresses correctly. If they receive the messages then I would bet something is getting screwed up with your web app.

Some other things you might check:

1. Mail queues on the Exchange server
2. That your Default SMTP Virtual Server is set to relay emails from the ip address of your web app.
3. Make sure your exchange server is getting the correct DNS/MX Records from your internal DNS server

Daniel

 

[dvannoy]

OK,

I tried to telnet using

telnet mail.mydomain.com 25

got an error message stating "cannot open connection to host on port 25"

I did tried to telnet right from the mail server.

 

[dvannoy]

it works using the IP address only, not the name.

 

[danielwestendorf]

Sounds like your DNS is not resolving correctly then. You can try and figure out the DNS issue or just point your web app at the IP address and see if that resolves the issue.

dw

 

[dvannoy]

In my local AD, I don't have an MX record setup. we use godaddy and that's where I setup the MX record at to point to an IP address on my firewall.

do I need to setup an MX record in my local AD?

Thanks for your help

 

[dvannoy]

you know I don't think the relay is setup correctly. can you tell me how to do that?

Thanks

 

[danielwestendorf]

Depending on your setup, probably not. MX records are so a system can go "Who handles mail for this domain?" Since you already know that, and aren't querying that dynamically, no.

From the same box as your webapp, can you ping your exchange server via the hostname? You are using the FQDN right? Like "Exchange.yourinternaldomain.lan"?

Can you do an nslookup of the exchange box's hostname from your web app box?

dw

 

[dvannoy]

I can ping the exchange server using the the FQDN

mymailserver.mydomain.local

I dont a an entry for exchange.myserver.mydomain.local

nslookup works correctly.

I think it's a relay issue.

 

[danielwestendorf]

Okay, if you can ping mymailserver.mydomain.local, is that the hostname you're using in the web app?

Can you telnet from your webapp box to exchange using the FQDN and attempt to send an email to an external account?

In the Exchange System Manager> YourServer>Protocols>SMTP>Default SMTP Virtual Server>Properties>Access Tab>Relay Button do you have which clients the server will relay for restricted?

dw