title: Email regular expression validator for allowing whitespace at start and end
body: <p>Following expression work well for email validation with asp.net but does not allow whitespace at start and end.</p>
  
  <pre><code> ^(([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5}){1,25})+([;.](([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5}){1,25})+)*$
  </code></pre>
  
  <p>Have any way to allow whitespace?</p>
  
  <p>Here is full asp.net markup, I can not trim before validation.</p>
  
  <pre><code> &lt;asp:TextBox ID="txtEmail" runat="server" MaxLength="100" CssClass="textbg text"&gt;&lt;/asp:TextBox&gt;
  
   &lt;asp:RegularExpressionValidator ID="EmailValidator" runat="server" ErrorMessage="Email is not vaild."
              ForeColor="Red" ControlToValidate="txtEmail" ValidationExpression="^(([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5}){1,25})+([;.](([a-zA-Z0-9_\-\.]+)@([a-zA-Z0-9_\-\.]+)\.([a-zA-Z]{2,5}){1,25})+)*$"
              ValidationGroup="register"&gt;Email is not vaild.&lt;/asp:RegularExpressionValidator&gt;
  </code></pre>