Some large display ad networks like Facebook and Twitter allow precise targeting by uploading a list of email addresses from your existing customers and then using the resulting custom audience to run super targeted ad campaigns.
It is possible to create custom audience from email list in Google Display Network / AdWords Campaigns?
The answer is NO - at this moment (2015) Google Display Network does not have an option of using list of emails for ads targeting. However, there are rumors that Google is working on making email targeting possible - so it may change soon b/c of their competition already provide such option:
Email targeting is available on other ad networks - pls see below
With Custom Audiences, you can reach customers you already know. Just upload a list of contact info like email addresses or phone numbers
You can now create tailored audiences from lists of email addresses from your own customer relationship management (CRM) database
Looks like LinkedIn Ad network does not have this option.