Blog Help!

Hello there!  You!  Yes, You!

Since you are popping by...  Would you mind helping me out with a couple of questions?  Here's the issue... When I comment on other blogs, I often (but not always) get a "Delivery Status Notification (Failure)" email.  I have googled the issue and it looks easy to fix, but when I try to follow the steps to "fix" the problem, I can't seem to figure it out. 

Here's what I've done so far.  I thought it was an issue with my Yahoo account being linked to this blog, so I created a gmail account and now the gmail address shows in the top right corner of my dashboard.  I can't find the Yahoo account embedded anywhere else in the settings, so that's the only change I've made.  I tried to comment again on a blog and I got another notification, again through Yahoo, so that address must be buried there somewhere.

So... two questions...

1.  Does failure to deliver mean that my comment isn't going through at all?  Or, does it mean the receiver is just not getting an email saying there is a comment waiting for them to view? (I seem to get the message when a blog's owner is moderating comments before allowing them to post)

2.  Is there an easy fix to this?  If so...could you steer me in the right direction?  I am obviously not tech savvy!

Thanks so much for any help :)