Is it possible to write C# code as below and send email using network in different country?

Question

Is it possible to write C# code as below and send email using mnetwork in different country?

MSExchangeWebServiceURL = mail.something.com/ews/exchange.asmx

It's a web service URL. This works great when I run the same code from home network, my friends home network anywhere around, but when I run it from my client's location in Columbia it fails.

I have a valid user name and password on that Exchange Server. Is there any configuration that I can set to achieve this?

BTW this code below works when I run it within office network and any network within any home network. I have tried it at least with five friends network in Plano, Texas. I want this code to work running from any network in another country.

My client in Columbia can connect to the web service using a browser using the same user name and password, but when I run the code above it is not able to connect to our web service.

Answer 1

If you are asking if the code works (which it doesn't look like you are but it's in your post) you should ask on stackoverflow. If you are wondering why it won't work from home Its likely because the edge server is not set up to relay, and if you are at home and not vpn'd into the network that's all you have access to.

Answer 2

EDIT: Based on the comments and updated post, I would wager that the client location has a proxy server or firewall that is blocking the traffic. The client probably needs to add the relevant domain to whatever "whitelist" they have.

If it works from an internal network, then the problem is most likely not the code. You need to debug it and see what error turns up when running it outside of the network. Then check the logs on the firewall and the target exchange server to see what is happening.

One possible culprit is that the DNS name is not setup outside the office network, or that the office firewall is not setup to pass traffic (or only to pass SMTP traffic) from the internet to the server in question. Another is that Exchange Web Services is not setup properly to accept requests from the outside world. That can be tested from http://www.testexchangeconnectivity.com/.

If this isn't enough for you to get there, post more info about what errors you are seeing. "It isn't working, I want it to work" kind of reminds me of the Star Trek TNG episode about the species who kept telling Geordi to "make it go".

Answer 3

You need to break this down a bit:

What's the MSExchangeWebServiceURL? I don't need to know your real URL, but is this resolvable from your home network? i.e. is it an internal DNS host (server.mycompany.local) or is it an externally-resolvable DNS host (mail.yourcompany.com)?

If it's internal, like another poster said, you'll at least need to VPN in (or replace that with the external URL).

I'm not a big C# guy, but I'm guessing it's looking for your Exchange Server hostname or FQDN, and since the type is "SMTP" it wants to establish a TCP session with your mail server. You can likely test this out by opening up your command prompt and trying to telnet <MSExchangeWebServiceURL> 25. When that works, my guess is your code will work too.