>>>Hi,
>>>
>>>I am working on a new feature of my ASP.NET app. In a nutshell, the asp.net application sends an email which has a URL.
>>>The URL, when clicked, would open a page of the application.
>>>If I do it all from my desktop, it works. That is, I receive email in my Outlook, then click on the URL, and the page opens.
>>>
>>>But if I receive the email on my iPhone and click on the URL, the page does not open. Message is:
>>>
>>>"Safari cannot open the page because it could not connect to the server."
>>>
>>>The URL has localhost. Is this why the page cannot be opened?
>>>Or, how do I make my iPhone see the server?
>>
>>It sounds like your web server is on your desktop computer, which is why it works from a URL that includes "localhost". That's also valid for an iPhone but it means to look on the iPhone itself, so unless you're running a web server instance there, it won't work.
>>
>>If you want your iPhone to find the web server on your desktop, you need to have 2 things:
>>
>>- An address which ultimately resolves to your desktop
>>- A way for your iPhone to reach your desktop
>>
>>If you're just testing how things look on an iPhone, the easiest thing is to connect it to your local WiFi. Then, use ipconfig in a CMD window on your desktop to get its IPv4 address (e.g. 192.168.1.123). You can then send an email with a URL like http://192.168.1.123/MyAppStartPage.aspx . The firewall on your desktop must be set to allow incoming connections on http and/or https as needed.
>>
>>If you have problems with a browser not wanting to go to an IPv4 address you may need to set up a static DNS entry on your router that points to the IP address of your desktop e.g.
>>
>>DLDesktop 192.168.1.123
>>
>>Then the URL you send to your iPhone would be something like http://DLDesktop/AppStartPage.aspx
>>
>>The firewall on your desktop must be set to allow incoming connections on http and/or https as needed.
>>
>>Alternately, it may be possible to set up a static host name on an iPhone but I have no idea how to do that.
>>
>>It's more complicated to make your desktop web server accessible from the public Internet and from a security PoV I wouldn't recommend it.
>
>You are correct that I am simply testing how the page will look on my iPhone. I will carefully follow your suggestions and see if it lets me do it.
>Otherwise, the beta test customer will have to do it. They have ITs and it will be their responsibility to make sure that my web application is accessible from the mobile devices.
>Thank you!

Al already explained the probable steps better than I would have. Let me add 2 hints:
If following his outline you don't succeed, try the setup menu of your router to check if WLAN and desktop are in the same subnet - sometimes WLAN and normal LAN are separated for security reasons, before adding DNS entry there.

And paranoid me would have put more emphasis on the emboldened part ;-)