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MailerPress: Sending Emails with the WordPress Default Provider

Here are the steps to send your email campaigns using the built-in WordPress Default provider in MailerPress, along with best practices for deliverability and bounce management.

How it works

The WordPress Default provider uses the native wp_mail() PHP function to send emails. It does not connect to any external API directly — instead, it relies on your WordPress hosting environment or a third-party SMTP plugin to handle the actual delivery.

This means:

  • No API key is required. The provider works out of the box.
  • No account to create. There is no external service to sign up for.
  • Any SMTP plugin is compatible. If you use a plugin like Fluent SMTP, WP Mail SMTP, Gravity SMTP, or Post SMTP, it will automatically intercept emails sent by MailerPress and route them through your configured SMTP server or transactional email service.

#1 – Enable the WordPress Default provider

  1. Go to your WordPress admin, MailerPress, Integrations, Email Service Providers.
  2. Find the WordPress Default card.
  3. Click the Settings icon and enter a default sender email address and a default sender name.
  4. Save changes.
  5. Toggle the switch on the WordPress Default card to enable it. Open the dropdown menu (three dots) and click Set as primary to make it your default sending service.

#2 – Send a test email

  1. On the WordPress Default card, open the dropdown menu (three dots).
  2. Click Send a test email.
  3. Enter a recipient email address and click Send.

You should receive an email with the subject “This is a Sending Method Test”. If you don’t receive it, check the section below about SMTP plugins.

#3 – Configure sending speed

Go to MailerPress, Settings, Sending Speed to choose a sending profile:

  • Prudent (Recommended for shared hosting) – 50 emails per batch, every 10 minutes (~300/h). Prevents overloading your server.
  • Balanced – Suitable if you have a dedicated SMTP plugin configured with a reputable provider.
  • Performance – Only use this if your SMTP plugin is connected to a high-volume transactional service (Brevo, Mailgun, Amazon SES, etc.) with confirmed rate limits.

The default is 50 emails every 10 minutes. This conservative setting protects you from being flagged as spam by your hosting provider.

Why you should use a third-party SMTP plugin

By default, WordPress sends emails using the PHP mail() function, which has significant limitations:

Deliverability issues

  • Emails sent via PHP mail() often land in spam or are silently dropped by recipient mail servers.
  • Most shared hosting providers do not configure proper SPF, DKIM, or DMARC records for outgoing mail.
  • Some hosts throttle or block outgoing email entirely.

No visibility on delivery

  • PHP mail() provides no feedback on whether an email was actually delivered, bounced, or marked as spam.
  • Without an SMTP plugin, you are sending emails “blind” — you have no way to know if they reached the inbox.

What an SMTP plugin solves

An SMTP plugin intercepts all wp_mail() calls and routes them through a real email service (Gmail SMTP, Brevo, Mailgun, Amazon SES, SendGrid, etc.). This gives you:

  • Authenticated sending (SPF, DKIM, DMARC) — dramatically improves inbox placement.
  • Delivery logs — see which emails were sent, delivered, or failed.
  • Higher sending limits — your email volume is no longer constrained by your web host.

Any of the following plugins work seamlessly with MailerPress via wp_mail():

PluginNotes
Fluent SMTPFree, supports many providers
WP Mail SMTPMost popular, beginner-friendly
Gravity SMTPBy Gravity Forms team
Post SMTPIncludes email logging

#4 – Enable bounce tracking

Even though WordPress Default does not connect to an ESP API directly, bounce tracking is fully supported — because your SMTP plugin routes emails through a real provider, and that provider can send bounce notifications back to MailerPress via webhooks.

How it works

Your SMTP plugin (Fluent SMTP, WP Mail SMTP, etc.) sends emails through a third-party provider (e.g., PostMark, Brevo, Mailgun). That provider knows when an email bounces. By configuring a webhook in that provider’s dashboard, you tell it to notify MailerPress whenever a bounce occurs. MailerPress then automatically flags the contact in your Audience.

Step-by-step setup

  1. Open the WordPress Default settings modal in MailerPress, Settings, Providers (click the Settings icon).
  2. Under Bounce Tracking Provider, select the provider that your SMTP plugin uses to deliver emails. Available providers:
    • Brevo
    • Mailgun
    • Mailjet
    • PostMark
    • SendGrid
    • Amazon SES
    • Emailit
    • SMTP2GO
    • Resend
  3. Once selected, MailerPress generates a Bounce webhook URL specific to that provider. Click Copy to copy it.
  4. Go to your provider’s dashboard and paste the webhook URL in their webhook / bounce notification settings. The exact location varies by provider — refer to the provider-specific documentation on mailerpress.com/docs/bounce-tracking for detailed instructions.
  5. Save changes in MailerPress.

Important: The provider you select in the dropdown must match the provider your SMTP plugin is configured to use. If your SMTP plugin sends emails through PostMark but you select Brevo in the dropdown, the webhook URL will be wrong and bounce tracking will not work.

Example

If you use Fluent SMTP configured with PostMark:

  1. Select PostMark in the Bounce Tracking Provider dropdown.
  2. Copy the generated webhook URL (e.g., https://yoursite.com/wp-json/mailerpress/v1/esp/bounce/postmark).
  3. In your PostMark account, go to Servers → your server → Webhooks → Add Webhook, paste the URL, and select Bounce as the event type.

What if I don’t use an SMTP plugin?

Without an SMTP plugin, WordPress sends emails via PHP mail(), which provides no bounce feedback. In this case, bounce tracking cannot work. We strongly recommend installing an SMTP plugin connected to one of the supported providers above — see the section below for recommendations.

#5 – Track your bounces

Go back to MailerPress, Audience, and use the Bounce filter to see your bounced contacts.

Bounced contacts are automatically flagged and excluded from future sends.

#6 – When to use WordPress Default

The WordPress Default provider is ideal for:

  • Getting started quickly — no account or API key needed.
  • Low-volume sending — newsletters to a small list (under 500 contacts).
  • Testing and development — verify your campaigns work before connecting a dedicated ESP.
  • Sites already using an SMTP plugin — if your SMTP plugin is already configured and you don’t need bounce tracking in MailerPress.

For production use with larger lists, we recommend switching to a dedicated ESP provider for better deliverability, bounce tracking, and sending analytics.