500 – Internal server error

When I hit the Check now button
the email get’s read.
I get the message below and the url when I get the message:

http://www.jesusiowe.org/wp-admin/tools.php?page=post-by-email&check_mail=1

500 – Internal server error.

There is a problem with the resource you are looking for, and it cannot be displayed.

https://ww.wp.xz.cn/plugins/post-by-email/