Under 24 hours (unless it's a weekend).
There are currently only 3 orders waiting approval, and those were ones that flagged-up "fraud check required" from WorldPay. So unless yours is one of those your download email has been sent - (we send emails to all "fraud" people asking them to verify their orders, so if you don't have an email from us yours isn't counted as one of those).
Far more common reasons people think we've not sent the details are (a) They paid with PayPal and have a different email address for payments, which is the one we send all details to (b) Junk/Spam filter ate it (c) They ordered using a different email address totally.
Basically - contact support if you've been waiting > 24 hours and haven't got anything at all.
People don't quit playing because they grow old.
They grow old because they quit playing.