Cant send emails via Newsletter Extension

Hi,
I am using Opencart 2.3.0.2. I had the Newsletter installed in extension under "BurnEngine". Although, i can see the subscribers and export the list, i am not able to send email from the "Mail" section under "Marketing".
Please advise what is wrong or what am I doing wrong.

Have you contacted the extension author about that?

Hi there,
Yes i did contact them, just got to know that the extension is limited to only collect emails and export them and is supposed to be used for third party applications like mailchimp. Thanks for reverting.