In the past, when a donor donated by check in U.S. dollars, it was your responsibility to print out the receipt and mail it to your donor.
I'm happy to let you know that as of 23/06/2020, IsraelGives will mail all U.S. donors their tax-receipts, so you no longer need to handle this. There is no extra cost to you.
As always, you can obtain a PDF copy of the tax-receipt through the Donations section of your IsraelGives account.