Does not work with Postie?

Hi there, I am using your plug-in along with Postie. The Postie posts (sent via email) are not being sent to subscribers, though regular posts are. Any thoughts as to why, and how to correct?

SS v1.57
Postie v1.6.2
WOrdpress v4.0

Thanks in advance!

https://ww.wp.xz.cn/plugins/simple-subscribe/