By default the UIWebView only responds or loads http protocol related URI. For the webview to respond to mailto URI, add the following code as implementation of shouldStartLoadWithRequest method to the UIWebViewDelegate.

  1. - (BOOL)webView:(UIWebView *)webView shouldStartLoadWithRequest:(NSURLRequest *)request navigationType:(UIWebViewNavigationType)navigationType {
  2.     if ([[[request URL] scheme] isEqual:@"mailto"]) {
  3.         [[UIApplication sharedApplication] openURL:[request URL]];
  4.         return NO;
  5.     }
  6.     return YES;
  7. }