Notification emails not being received when my commit it commented on

Prior to last week when one of my commit's was commented on (on a repository i'm watching) i would receive an email notification to my primary email address.

I have not changed the config - but it no longer seems to work for me.

I've checked all the settings i can find and it all looks correct. I have since changed my primary email to test just incase of it being a problem with my email provider - and that has made no difference.