WP Ticket is a very easy to use helpdesk and support ticket management system to receive, process, and respond to service requests.
Software Issue Manager allows to track the progress and resolution of every project issue in a productive and efficient way.
WP App Studio is a Visual WordPress Development Platform for building custom post types, fields, taxonomies, widgets, forms, notifications, charts ...
MailCWP, Mail Client for WordPress. A full-featured mail client plugin providing webmail access through your WordPress blog or website.
Queue, Throttle, Send SMTP email through multiple providers. Automatic re-send when non-delivery received.