Two issues with user registration

Hi All,

I am having two issues with the new blogs registration process:

A. Which file is responsible for the new blog registration confirmation? I mean the page that appears when new users click on the activation link in their email to activate their newly created blog

I need to customize this page so that it can have the look and feel of our website but not sure which file to edit

B. All new blog activation emails goes directly to the SPAM folder, despite of which email provider our users are using...so any advice how to avoid this?

Thanks in advance for your time