The Overview page will provide some high-level numbers as to the results of your email OneTouch job. 

Here is a quick review of the column to let you know how it is calculated

Queued - Number of valid recipients originally selected as email recipients.

Sent - Number of contacts processed to be sent. *Some recipients may still error before being sent.

Delivered -  Number of emails successfully delivered. Excludes errored or previously unsubscribed email recipients.

Undelivered - All currently processing emails and any errored or previously unsubscribed recipients.

Open Rate - Number of times emails have been opened to a number of emails delivered.

Unique Open Rate - Single count for each recipient that has opened an email opened to a number of emails delivered.

Unsubscribed - Number of emails that have been unsubscribed from this email job.

Clicks - Total number of times email recipients clicked a link within the email.