E-mails to suppliers

E-mails to suppliers

Hi,
i want to upload a spread sheet every day and send an e-mail to our suppliers every day (or when triggering a button?) with info from the spreadsheet lines.
The supplier e-mail would be on each line.
Unfortunately, when creating a scheduled automation, the form to defnie the e-mail won't let you select the e-mail address field from the form.  Why is this?  How can i trigger this?

regards,
Lieven