Apple recently removed the option to purchase Apple Store or iTunes gift cards by email from its U.S. website, eliminating the ability to buy e-gift cards.
The option to purchase physical Apple Store or iTunes gift cards by mail remains on Apple's website, while both physical and e-gift cards remain available from third-party resellers such as Walmart and Staples.
Apple previously allowed customers to purchase digital gift cards and send them by email. The purchaser selected a card design and value, and composed a birthday wish or similar message for the recipient.
Update (September 16): Apple has restored the page for purchasing gift cards by email in the United States.