Here is an example:
Thank you for requesting [title]. I hope you will have the opportunity to read it soon--you can download it to any reading device. If you have already read and enjoyed this book, please take the time to submit your feedback via NetGalley and write a review on [Amazon/Goodreads/other preferred outlet websites]. Your participation is appreciated!
If you would like more information, or to otherwise interact with the author, please contact [publicist/marketer email address].
If you have any questions about downloading please reach out directly to NetGalley’s support team—they are always happy to help! You can reach them through the Knowledge Base. Click here for more information about how to leave feedback via NetGalley.
For more information regarding [publisher name] and our list of upcoming books, kindly visit us at [website].
Thanks for your time & support of our books!
And another example with more specifics:
It's release day for [book title] by [author]! Thank you so much for requesting a copy and taking the time to read and review it. Thank you so much to everyone who has already sent me a link to their review! If you haven't yet, please take a few minutes to cross-post your review to Goodreads, Amazon, and/or Barnes & Noble! Your reviews do so much to help with a book's success.