Content publishing and confirming comment via email in drupal 7?
Currently there is no module for this functionality afaik.

To implement this one,


You need to pull the mails from server
Processing the mails and performing other operations like checking whether the user is an admin
After the processing create the content
Finally add a cron job to perform this operation regularly


This article provides info about how to achieve this feature in drupal 7 with combination of several modules.

However authenticating using the sender's mail will be a security risk. For example if the admin mail ID is exposed then anyone can send mails as admin by altering the header information.