Emailed gift cards are not always sent within minutes. On the website Amazon states that they can take up to 24 hours and can be cancelled before they are delivered. I chose to cancel my order and buy printable gift cards instead. Now the order for the emailed cards does not appear on my Amazon account, but my bank account has been charged for both the emailed cards AND the printable. I am now concerned that my recipients might not let me know if they have problems with the emailed cards (which they did receive, fortunately). I would recommend just using the printable option and emailing the PDF. Ultimately, the only thing that matters is the code.
I was also disappointed that I could not use my own gift card balance to buy the gift cards, it seems a petty gesture by Amazon.