ActiveCampaign Postmark for WordPress
The officially-supported ActiveCampaign Postmark plugin for Wordpress.
Sumada Kaabaha: postmark
PostmarkApp Email Integrator
Enables your WordPress site to send emails via PostMarkApp API.
PostMarkApp Mail Replacement
A simple plugin that replaces the default wp_mail function with PostMarkApp (http://postmarkapp.com/).
Postmark Open to EDD Customer Note
Add a Customer Note when a Postmark-delivered email has been opened by an EDD Customer