When viewing an email from Online Express in the Gmail or Inbox app, some users may notice that the email does not render responsive formatting. Instead, the email shrinks to the width of the mobile device. Emails opened in the webclient do render responsive formatting, though.
If the email address is not a Gmail/Gmailified account: This is a limitation with Gmail's scope of support for media queries, which are used in Online Express emails to implement responsive formatting in the email client.
If the email address is a Gmail/Gmailified account: We are currently evaluating this issue and will update this article as we have further updates.