Description

Expressive SMTP Pro

Secure, Reliable Email Delivery for WordPress (Microsoft 365 OAuth + Advanced Logging)

Stop losing emails.
Stop fighting SMTP authentication errors.
Start sending securely — properly.

Expressive SMTP Pro gives you enterprise-grade email delivery for WordPress, with full support for Microsoft 365 OAuth 2.0, detailed logging, and intelligent configuration controls — all wrapped in a clean, professional UI.

Built for agencies, developers and growing businesses who need email to just work.

Why Expressive SMTP Pro?

WordPress’ default mail function is unreliable.
Shared hosting mail servers get blocked.
Basic SMTP passwords get disabled.
Microsoft 365 tenants block legacy authentication.

Expressive SMTP Pro solves all of it.

Modern OAuth 2.0 for Microsoft 365

No stored passwords. No insecure authentication.
Full delegated OAuth flow with automatic token refresh.

Secure, Encrypted Token Storage

Refresh tokens are encrypted before being stored in the database.

Intelligent Logging & Debugging

See exactly what was sent, when, and whether it succeeded — including error responses.

Clean, Developer-Friendly Architecture

Built properly for production use — not a hacked-together mail override.

Core Features

Microsoft 365 OAuth 2.0

• Connect via Microsoft Entra ID
• Delegated Graph Mail.Send support
• Automatic access token refresh
• Disconnect & re-authorise controls
• No reliance on SMTP AUTH if blocked

Perfect for modern M365 tenants with security defaults enabled.

Flexible Authentication Modes

• Basic SMTP (username/password)
• Microsoft 365 OAuth 2.0 (Graph API)
• Force From Email
• Force From Name

Switch authentication method with a single toggle.

Advanced Logging

• Success & failure tracking
• Error message capture
• Timestamped entries
• Context-aware logging
• Debug mode toggle

No more guessing why emails aren’t sending.

Security First

• Capability checks (manage_options)
• Nonce verification
• Sanitised settings
• Encrypted refresh tokens
• No front-end exposure
• No unnecessary external dependencies

Agency-Friendly Controls

• Licence key activation
• Plugin Hub Suite compatible
• Clean admin UI
• Minimal footprint
• Built to sit alongside professional plugin stacks

Who It’s For

• Agencies managing multiple WordPress sites
• Businesses using Microsoft 365
• WooCommerce stores that rely on transactional email
• Developers who need reliable staging & production email
• Sites where security defaults block SMTP AUTH

If email matters to your business, this plugin is for you.

Use Cases

• Contact form delivery via Microsoft 365
• WooCommerce order emails
• Password reset emails
• Membership notifications
• CRM integration notifications
• Secure corporate email sending

Technical Overview

• Uses Microsoft Graph API for OAuth mail sending
• Delegated Mail.Send scope
• Automatic token refresh logic
• Compatible with modern Microsoft security defaults
• Hooks into wp_mail
• Fully WordPress standards compliant

What Makes It Different?

There are free SMTP plugins.

There are bloated SMTP plugins.

There are outdated SMTP plugins.

Expressive SMTP Pro is built for modern Microsoft environments, with clean code and no unnecessary clutter.

It doesn’t just “send mail”.

It sends mail properly.

Requirements

• WordPress 6.0+
• PHP 7.4+
• Microsoft 365 account (for OAuth mode)
• Entra App Registration (for OAuth connection)

Pricing

Expressive SMTP Pro is a paid plugin.

Single site licence
Ongoing updates
Priority support
Future feature roadmap

Ready to Stop Losing Emails?

Install Expressive SMTP Pro and connect your site to Microsoft 365 the right way.

Secure. Modern. Reliable.