There's a couple of reasons your inboxes may not be sending from Uptics. This is usually linked to your email provider connection with Uptics.
Microsoft
For Microsoft inboxes, there's two common reasons for 'Stopped State' issues:
Gmail
For Gmail inboxes, the most common solution for solving this is Basic reauthentication of your email inboxes.
Other
For other email providers, please see the this article.
If you follow the steps in the articles above and your sending issue is not resolved, please contact customer support.