REST HTTP API
You can send email using the REST HTTP endpoint. This allows you to send a single message or a batch of messages in a single API call.
SMTP is not an API, but a protocol used to inject email. Delivery details of each message can be customized by adding X-headers. You can create authorized users for SMTP sending through the API. Multiple SMTP servers can be configured.
Pipe email into a Linux command-line program from the same server as your GreenArrow install. GreenArrow provides programs compatible with both sendmail and qmail. This is not an HTTP API, but a standard, well-documented interface for injecting email.
Marketing Studio APIs
GreenArrow Studio's API has endpoints to schedule email campaigns and create automatically triggered autoresponders. Autoresponders can be triggered by an API endpoint and can contain additional replacement data, which together provide a triggered email template feature.
GreenArrow Studio's API provides the ability to manage subscribers, mailing lists, custom fields, segmentation criteria, and suppression lists. Fire off bulk subscriber imports and check on their status.
Instead of importing subscribers, you can use GreenArrow Studio's Remote Lists feature to your remote database, run an SQL query, and get a custom subscriber list for each campaign. This can be scheduled through the API.
Automatically respond to changing delivery conditions through Dynamic Delivery throttle programs. Intelligently split mail over multiple IP addresses using VirtualMTAs, and hand email off to other SMTP servers with Relay Servers.
Receive email at incoming email domains and mailboxes at those domains. Mailboxes can be configured to forward email, deliver it to user mailboxes via a Maildir/Mbox file, deliver to a POP3 user, or pipe to a program for delivery.
Programmatically customize email delivery with a hook to override default delivery behavior.
Marketing Studio's Special Sending Rules feature allows you to fully customize emails by writing Perl or PHP code that can be called for each email sent.
Email Service Providers who deploy GreenArrow Marketing Studio for their users are able to manage customer accounts, manage user accounts, and get email volume and subscriber counts for billing all through the APIs.