title: Why are cookies unrecognized when a link is clicked from an external source (i.e. Excel, Word, etc...)
body: <p>I noticed that when a link is clicked externally from the web browser, such as from Excel or Word, that my session cookie is initially unrecognized, even if the link opens up in a new tab of the same browser window.</p>
  
  <p>The browser ends up recognizing its cookie eventually, but I am puzzled as to why that initial link from Excel or Word doesn't work. To make it even more challenging, clicking a link works fine from Outlook.</p>
  
  <p>Does anybody know why this might be happening? I'm using the Zend Framework with PHP 5.3.</p>