Etsy claims they do not let Etsy sellers download Etsy customers' emails in bulk, because they do not want Etsy sellers sending spam to Etsy customers. They claim it is a privacy issue and imply Etsy sellers will misuse the data.
By the letter of the law, it is only spamming if your main intent is to generate new sales without the customers' prior consent to contact them. What if Etsy closes your shop and you need to inform your customers of your new website? That is not spam, it is informational.
Many believe Etsy s attempts to limit your access to your Etsy customers' emails data is primarily so you do not draw business away from the Etsy site and create a one-on-one relationship with your customers. Well, if Etsy closes your site, why not?