title: Opening my iOS existing app from an email app which uses Gmail account doesn't work
body: <p>During the signup process, the user receives an email with "Activate Account" button and I want to able to open my existing app when this button is pressed. </p>
  
  <p>I don't need to be redirected to AppStore.</p>
  
  <p>I don't want to use branch.io! There are similar questions on stackoverflow, but all the responses has reference to branch.io or they are too old to be valid.</p>
  
  <p>I added deep linking file on the website and I added the associated domain and <code>application(_ application: UIApplication, continue userActivity: NSUserActivity, restorationHandler: @escaping ([Any]?) -&gt; Void) -&gt; Bool</code> method in AppDelegate, in Xcode. </p>
  
  <p>The button inside the email works if I am logged in in Safari and I don't use a native email app, but I need to be able to open the app from the email app.
  Is there any chance to be able to do that? </p>
  
  <p><strong>Edit</strong> : The app is opened from the email app, unless if I use Gmail. My Mail app used Gmail as Default Account (Go to Settings -> Mail -> Default Accounts). The issue is available only for Gmail client.</p>