Quick Send allows Users to quickly send an email directly from the email editor, rather than going through the campaigns menu.*
To send an email via Quick Send, start by navigating to the Emails menu and create a new email, or edit an existing one. From here:

• Once you have finished editing, select Save
• Then select Share:
  • From the dropdown options, choose Quick Send.
• Within the campaign editor that appears:
  • Choose your Recipients - who would you like to send this email to?
  • Set your Date & Time - choose to either Schedule immediately, or schedule this email to be sent at a set date and time in the future. 
  • Some users will also have the option to make this a recurring campaign.
• Once your recipients and schedule are set, select Send to complete and activate your Quick Send campaign.

You can access reporting for a Quick Send campaign just like any other - it will be saved in your campaigns menu, using the name of the email, plus (Quick Send), e.g.: "Data Discovery (Quick Send)"

* If you want to add Triggers or Conditions to your campaign, or if you are an Admin, save your email and go to the Campaigns menu to create a campaign.