POST to send download email for the specified order...

/api/v2/orders/:id/send_email?reset_expiration=false

/api/v2/orders/:id/send_email?expiration_date=2011-03-07T15:08:02+00:00&download_limit=10

/api/v2/orders/:id/send_email.xml?expiration_date=2011-03-07T15:08:02+00:00&download_limit=10

Example result...

<?xml version="1.0" encoding="UTF-8"?>
<message>Ok.</message>

NOTE: reset_expiration is an optional boolean, and defaults to true if not present. If true, the expiration date will be set to whatever is selected in Settings → General or provided by the param expiration_date and the download limit will be set to whatever is selected in Settings → General or download_limit if present. Bothexpiration_date and download_limit are optional and if present override the default values option.