members not receiving notification emails for new posts etc

Hia

A couple of my members have informed me that they are no longer receiving notification emails for new posts or private messages in their email accounts, even though they were before.

I've been into their profiles to ensure the Pm and new posts notification option is checked as "Yes" and they are.

I've asked them also to check their email junkmail folder, and they are saying the notification emails are not in there either.

Does anyone know whats going on with this?

thanks in advance

Hi I'd really appreciate some input please.

This problem hasn't resolved itself for my member

wrong place sorry