Notifications for new post are not sent

Hi,

When adding a new post (blog) to my site, I remarked the notifications to subscribed users are not sent.

I cannot figure out what is wrong. In my opinion all the settings are ok!? (see bitmaps)
I also tried a resent, see birmap with arrow, but is doesn't work.

What can be wrong?

Thank you for your answer, Kind regards, T.W.van Urk