Postmark is recognised as one of the fastest transactional email service enabling quick transmission of emails between subscribers and users with its delivery time recorded to be less than 10 seconds. It aids in finding out the mails that are actually opened by the customers and the time spent by them in reading the mails they receive. Users are provided with a searchable history for a time period of 45 days through which they can track down mails that are opened, rejected and bounced. It also helps in finding out the location of the customers at which the mails sent to them are notified and read. It consists of an official plug-in for WordPress.