You need to setup your Amazon AWS credentials in order to send emails via Amazon SES.
Otherwise, emails will be sent via your web server.
Set it in Settings →
View our Get Started guide →
If you charge your client(s) a fee for sending newsletters, they'll pay to this PayPal account. Also, don't forget to turn Auto Return ON in your PayPal account under Profile > My sellings tools > Website preferences so that your client will be automatically re-directed to the sending script after payment. Just use your website's URL for the Return URL to be able to save.
You'll need this license key to download the latest version of Sendy on our website.