First, What Is Email Deliverability?

Understanding what happens after you click “Send”.

Step 1: Your Site Sends the Email

WordPress passes the email to a mail system.

Step 2: The Receiving Server Verifies It

Providers like Gmail check your identity.

Step 3: Inbox or Spam?

This depends on trust and past sending history.

Shared Hosting Limits

Missing SPF or DKIM

No Bounce Handling

Sending Too Quickly

The Five Foundations of Reliable Email

2. Use external SMTP to send your emails

3. Send emails at a safe speed

4. Monitor bounces and complaints

5. Monitor & Test

Comparing Email Sending Methods

MethodWhat It IsIs It Reliable?
Basic Hosting MailBuilt-in PHP mail functionOften unreliable.
External SMTPSends emails through an external mail server via SMTPMuch more reliable.
External APISends emails through an external mail server via their APIBest for large or growing sites.