Hyperlink column in GridView doesn't like colon

I was building a table using the GridView control to display the names and email addresses out of a datatable that I constructed in the codebehind from an object array returned by the business layer of our 3-tier application. All went well till the part of adding a mailto hyperlink for the email. It took me a while to figure out that the hyperlink column doesn't take a colon for the NavigateUrlFormatString, so that took quite a bit of time figuring out. Unlike PHP, there are some places in code where ASP.NET can perform substitution while in other parts it treats it as a string literal, or worse yet, a malformed server tag. These errors don't show up at compile time so it's time consuming to start the application, log in and navigate to the desired page. I so wish I was on the JavaEE bandwagon right now with some sort of automated testing tool.