WordPress's default wp_mail() is unreliable, emails go to spam, providers rate-limit you, credentials sit in plaintext options. I built an SMTP plugin with 8 providers, one-click Microsoft 365 OAuth (no Azure AD registration), domain monitoring, and proper credential encryption.
Microsoft 365, Google Workspace, Amazon SES, SendGrid, Postmark, Mailgun, Brevo, generic SMTP. Pick what fits. One plugin, every major provider.
OAuth proxy built in, no Azure AD app registration. Click connect, sign in, done. Token refresh is automatic. Because making MSP techs register Azure apps for email is insane.
SPF, DKIM, DMARC checks for your sending domain. Alerts on misconfiguration. Fix suggestions. Because deliverability starts with DNS, not with SMTP settings.
Failed sends queued for retry. Configurable intervals and max attempts. Never lose a transactional email to a 30-second provider outage.
Every email, recipient, subject, provider, status, response, timestamp. Resend with one click. Search and filter. Because "did that email actually send?" shouldn't require checking server logs.
AES-256-CBC. Not in plaintext wp_options. Not base64 "encoded". Actually encrypted with site-specific keys. Because storing SMTP passwords in cleartext is negligent.
"SMTP Pro exists because I got tired of wp_mail() silently failing. The M365 one-click OAuth alone has saved dozens of MSP techs from the Azure AD app registration rabbit hole. The v3.x roadmap transforms it from SMTP plugin into a full email platform."
The engineering under the hood.
Per-provider limits prevent quota hits. Automatic throttling with queue overflow. Because SES has a 14/second limit and WooCommerce order notifications don't know that.
Delivery status from SendGrid, Postmark, Mailgun. Bounces, opens, clicks, spam complaints. Track what happens after the email leaves your server.
One-click config verification. Tests connectivity, auth, TLS, and actual delivery. Know it works before you rely on it.
Registers as a GLASS app. Config, logs, diagnostics, all inside the admin shell. Menu suppression for clean integration.
Connection testing, TLS verification, auth checks, DNS lookups, provider-specific troubleshooting. Fix delivery issues in minutes, not hours.
Success rates per provider, delivery time metrics, failure categorisation. Know which provider actually works best for your volume and email type.
Every AJT plugin shares the same security model, UX system, and licensing infrastructure. They're designed as one architecture that ships as independent packages. Back to the full ecosystem →
I'm always interested in challenging WordPress architecture problems. If you need a plugin built properly, let's talk.