Subscribe by email no longer sends email updates

Hi guys,

I have had some issues with the plugin. First, couple of days ago, when I published a new post, the plugin started sending multiple email updates (I have two of my emails set up and I got 10+ email updates until I turn off email in the plugin settings (put it to Never)). Then, before I published another post, I put the setting back to 'send email right after the post is published' and the email never came. It has been like that ever since.
I updated to latest version, lowered the number of emails in a batch to 4, the test-email is working, but I have no idea how to fix this. Can you help?

PS. Digests are not working either

Thanks,
Ivana