I've been using <meta content="width=device-width, initial-scale=1" name="viewport"> in responsive emails to render properly across mobile email clients and mobile browsers.

Recently i've read that viewport causes an issue on BlackBerry phones and display blank page. I don't have resource to check it by myself. Is it still an issue with newer BlackBerry phones with BlackBerry OS 10.

Reference: https://www.emailonacid.com/blog/details/C13/emailology_viewport_metatag_rendered_unusable