Discourse 2.6.0.beta1. If we make a Onebox youtube link all works fine. But the email corresponding to the post that goes out has a truncated and invalid URL. Why would this occur? Some of our users only use the email interface, so it’s a problem.
I’ve just tested this on an email testing service. Links to Youtube oneboxes don’t seem to be truncated on any of the email clients that I’ve tested it on.
Is this happening with all Youtube oneboxes or just specific ones? What email client are you seeing the issue on? Have you made any changes to your site’s email styles?