Email Shield — Multisite Email Governance Plugin for a SaaS Platform

Summary

A network-level custom plugin that gives a WordPress multisite SaaS platform full control over outgoing email, sender reputation and risky tenants — built for Amazon SES and SNS.

Challenge

On a multisite SaaS platform, every subsite sends email through a shared infrastructure. One tenant sending bad mail can damage sender reputation for everyone. The platform needed per-site control, trial-aware limits and an automatic response when bounce or complaint rates became dangerous — without giving network admins manual work for every incident.

Solution

I designed and built Email Shield as a network-activated custom plugin:

• Classifies marketing and system email through the pre_wp_mail filter before anything is sent
• Applies per-site and trial-aware sending limits across the network
• Suspends risky tenants automatically when reputation thresholds are crossed
• Processes authorized Amazon SNS bounce and complaint events through a secured REST API endpoint
• Includes SES tenant provisioning and FluentCRM sender controls
• Gives super admins a network dashboard and weekly reputation reports
• Stores its data with WordPress options and object cache — no custom database tables
• Uninstalls cleanly, leaving no orphaned data behind

Result

Delivered as a production release with full technical documentation, a CHANGELOG and a staging test plan, then promoted to production after member validation on staging.

Deliverables

Custom plugin, REST webhook endpoint, network admin dashboard, weekly reporting, documentation, staging test plan and clean uninstall routine.

Stack

WordPress Multisite, PHP, REST API, Amazon SES, Amazon SNS, FluentCRM