Please make sure email@example.com (not firstname.lastname@example.org, there is no R) is added to your safe senders list in your Amazon/Manage Your Content and Devices account and that your Kindle email address has been added to your NetGalley account (click on the silhouette icon at the top, then go to Profile and add your @kindle.com email). Once this is done go back to the book on your Dashboard or Shelf and select Send to Kindle again.
If the book doesn’t appear on your device within ten minutes or so restart your Kindle or try re-syncing your Kindle app.
You can also go to your Manage Your Content and Devices page in your Amazon account, then under Your Content filter to see Docs and if the book appears here, click on Actions and then click on "Deliver" and select the Kindle device/app you're using. Your device will sync wirelessly and the book will show up on your Kindle device or app.
Keep in mind that this book will appear on your Kindle as a Personal Document and not a book, so depending on your Kindle model you may have to look in the designated Documents section.
*If you receive any kind of error message when you press the Send to Kindle button, or once the file is on your device, contact support and let us know exactly what it says and we can look into it for you.