WooCommerce Transactional Email Setup via SMTP

The Problem

A customer places an order. WooCommerce sends a confirmation email. The email goes to spam because WordPress used PHP mail() to send it from a shared hosting IP with no authentication.

The customer thinks the order didn't go through. They contact support. Or worse, they dispute the charge.

This is preventable with 15 minutes of setup.

The Fix

Step 1: Install WP Mail SMTP

WordPress Dashboard → Plugins → Add New → Search "WP Mail SMTP" → Install → Activate

Step 2: Connect to SMTP Service

For Postmark (Recommended for WooCommerce):

1. Create a Postmark account at postmarkapp.com
2. Add your sending domain → verify DNS records (DKIM + Return-Path)
3. Get your Server API Token from Postmark
4. In WP Mail SMTP → Settings:
   • Mailer: Other SMTP
   • Host: smtp.postmarkapp.com
   • Port: 587
   • Encryption: TLS
   • Username: your Server API Token
   • Password: your Server API Token

For Brevo (Budget Option):

1. Create free Brevo account → get SMTP credentials
2. In WP Mail SMTP:
   • Host: smtp-relay.brevo.com
   • Port: 587
   • Encryption: TLS
   • Username/Password: from Brevo SMTP settings

Step 3: Domain Authentication

Add DNS records for your SMTP service:

• SPF include
• DKIM records
• DMARC record

See WordPress SMTP guide for detailed DNS instructions per provider.

Step 4: Test

WP Mail SMTP → Email Test → send to your personal email.

Then place a test order in WooCommerce. Verify the order confirmation arrives in inbox (not spam) with SPF/DKIM/DMARC passing.

WooCommerce Email Types

Email	Trigger	Priority
New Order (admin)	Order placed	High
Order Confirmation (customer)	Order placed	Critical
Processing Order	Payment confirmed	High
Completed Order	Order fulfilled	High
Refunded Order	Refund processed	High
Customer Note	Admin adds note	Medium
Reset Password	Customer requests	Critical
New Account	Customer registers	High

All of these route through WP Mail SMTP once configured. No per-email configuration needed.

Recommended Architecture

WooCommerce Store
├── Transactional Email (order confirmations, shipping, account)
│   └── WP Mail SMTP → Postmark ($15/month)
│       └── Authenticated, fast, dedicated transactional infrastructure
├── Marketing Email (campaigns, abandoned cart, post-purchase flows)
│   └── Klaviyo or Omnisend (separate ESP)
│       └── Separate infrastructure, separate reputation
└── Store Email (employee inbox)
    └── Google Workspace or Microsoft 365
        └── SPF, DKIM, DMARC on primary domain

This architecture ensures:

• Order confirmations always reach the inbox (Postmark's transactional infrastructure)
• Marketing campaigns don't affect transactional delivery (separate services)
• Employee email is properly authenticated

Practitioner note: WooCommerce transactional email going to spam is the #1 complaint I hear from ecommerce store owners who haven't set up SMTP. The fix is 15 minutes and $15/month. For a store doing $50K/month in revenue, even recovering 1% of orders that would have been lost to missed confirmations pays for Postmark's annual cost in a single day.

Practitioner note: If you're using a managed WooCommerce host (Pressable, Kinsta, WP Engine), they may have built-in SMTP. Check whether it includes authentication. Many managed hosts route through their own SMTP which may or may not have proper DKIM. Verify by checking email headers.

If you need WooCommerce email infrastructure set up correctly, schedule a consultation.

Sources

• WooCommerce: Email Settings
• WP Mail SMTP: Documentation

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v1.0 · March 2026