Here's a complete list of the error codes you can receive from the API.
The API only supports GET or POST, and some calls only support one or the other. This means you are trying to access an API call with an HTTP method you can't use.
You failed to pass a parameter that was required for this API call.
You used the wrong api_key parameter. Check that your client code is using the right API key against the API Settings page.
You are coming from an IP address that is not allowed according to your settings. You can add the IP to the list on the API Settings page.
The sig parameter you passed was not a correct signature hash of your shared secret and the sorted alphabetical list of the other parameters. For more details on this, see API Details.
You are passing invalid UTF-8 character as a parameter value.
Something's gone wrong on our end. Your request was probably not saved – try giving it a delay and trying again.
You tried to send to or access an invalid email address.
You tried to access a send_id that doesn't exist or doesn't belong to you.
You tried to access a blast_id that doesn't exist or doesn't belong to you.
You tried to use a template that doesn't exist. Double-check the name.
You tried to use a list that doesn't exist. Double-check the name.
You tried to import contacts from a site that we don't support.
You tried to import contacts, but we couldn't access them – probably either the username or the password was wrong.
You specified a time that didn't make any sense to us. We are very liberal with accepted time formats (anything that PHP's strtotime function can parse), but we recommend a standard format that includes timezone such as RFC 2822 (e.g. Sun, 22 Nov 2009 22:50:27 -0500).
Your account is not yet approved – until you are approved, you can only send emails to yourself. To get approval, email support@sailthru.com.
A few features of the API are only available to paid customers. To set up a paying account, email support@sailthru.com.
The email is on your site's permanent blacklist and should never be emailed.
This email has opted out of delivery from any emails coming from your site and should not be emailed.
This email has opted out of delivery from the specific template you are sending, and should not be sent this type of email.
This email has been identified as an email that should never be emailed.
This email has been previously identified as a hardbounce, so should not be emailed.
You attempted to set the From email to an email address you have not yet verified. You can verify additional From emails here.
You attempted to cancel an email that was already sent. It's too late to cancel after it's been sent.
You attempted to upload data in a character set that is not UTF-8 compatible, and therefore won't display properly in a message.
Miscellaneous catchall for other errors that have not been assigned codes