Access to preprocess variables in a custom block
It won't work.
If you use a preprocess function, the variables will be available in the template of the block.

I think that, in your case, you should edit the settings.php file and add the following line:

$GLOBALS['email1'] = 'example@email.com';


You'll be able to use the variable $email1 through the whole site.

Have in mind that it's not a good Drupal practice.