Didn't receive email notification

Hi,

I've just set up the Subscribe by Email plugin to notify subscribers immediately when a new post is published. I then published a test post but did not receive an email despite it appearing in the 'Sent Emails' log.

I'm also not receiving anything when I use the "send a test" feature.

Any ideas how I can get this working? Let me know if you need any more information.

Thanks,
Jenny