Josh Mckibbin

<p>The <a href="https://kibb.in/ssmtp" rel="nofollow ugc">Simple SMTP Mailer</a> plugin allows you to easily configure WordPress to use SMTP instead of the PHP mail function.</p>
<p><strong>This should only really be used in a development environment.</strong></p>
<h3>Simple SMTP Mailer Settings</h3>
<ul>
<li><strong>Host</strong>: The mail server (Defaults to smtp.gmail.com)</li>
<li><strong>Username</strong>: The username used for connecting to the SMTP server</li>
<li><strong>Password</strong>: The password used for connecting to the SMTP server</li>
<li><strong>Port</strong>: The port to use when sending an email (587, 465 or 25. Defaults to 587)</li>
<li><strong>Security</strong>: The type of encryption security to use when sending an email (TLS or SSL. Defaults to TLS)</li>
<li><strong>Debug</strong>: Enable debugging</li>
</ul>
<p>All settings can be overridden by assigning array values to the SSMTP_MAILER constant in wp-config.php. This is useful for automating local deployment.</p>
<pre><code>define(
    'SSMTP_MAILER',
    array(
        'host' => emailhost.com,
        'username' => username,
        'password' => password,
        'port' => 25,
        'security' => 'SSL'
    )
);
</code></pre>


Simple SMTP Mailer

Simplifies local development by configuring WordPress to use SMTP instead of the PHP mail() function

Kasuga

<p>SMTPify does one thing: replace WordPress’s default PHP mail with a reliable SMTP connection — no ads, no upsells, and no cluttering your admin menu.<br />
Just enter your host, port, and credentials. That’s it.</p>
<p>Features:</p>
<ul>
<li>Supports SSL/TLS, TLS (STARTTLS), and unencrypted connections.</li>
<li>Optional SMTP authentication with username and password.</li>
<li>Override the From address and display name site-wide, with an option to force your identity even when other plugins set their own From values.</li>
<li>Built-in test email tool to verify your configuration.</li>
<li>Persistent error log that records mail failures with recipient and timestamp, viewable on the settings page.</li>
</ul>
<p>What makes SMTPify different:</p>
<ul>
<li>All settings can optionally be fixed in code via constants in <code>wp-config.php</code>, making the plugin maintenance-free after deployment.</li>
<li>No external dependencies beyond PHPMailer, which is already bundled with WordPress.</li>
<li>Settings page kept out of the navigation sidebar, accessible via the Settings link on the Plugins screen.</li>
<li>No ads, no upsells.</li>
</ul>
<h3>Configuration</h3>
<h4>SMTP Server</h4>
<ul>
<li><strong>SMTP Host</strong> <em>(required)</em> — The hostname of your SMTP server (e.g. <code>smtp.gmail.com</code>, <code>smtp.sendgrid.net</code>).</li>
<li><strong>Encryption</strong> — Choose TLS (STARTTLS, recommended with port 587), SSL/TLS (port 465), or None (not recommended).</li>
<li><strong>SMTP Port</strong> — Automatically updated when you change the encryption type; override manually if your provider uses a non-standard port.</li>
<li><strong>Authentication</strong> — Enable to send your username and password to the server. Required by virtually all commercial mail providers.</li>
<li><strong>Username</strong> — Usually your full email address.</li>
<li><strong>Password</strong> — Your SMTP password or app-specific password.</li>
</ul>
<h4>Sender Identity</h4>
<ul>
<li><strong>From Email Address</strong> — The address that appears in the From header. Leave blank to use the WordPress default (<code>wordpress@yourdomain.com</code>).</li>
<li><strong>From Name</strong> — The display name shown to recipients. Leave blank to use <code>WordPress</code>.</li>
<li><strong>Force Sender Identity</strong> — When checked, SMTPify overrides the From address and name set by any other plugin or theme, ensuring all outgoing mail uses your configured identity.<br />
Note: <strong>some SMTP providers (including Gmail, Outlook, Yahoo, and iCloud) ignore the From address and replace it with the authenticated account address.</strong> This setting works as expected with dedicated mail delivery services (such as SendGrid, Mailgun, and Amazon SES) and self-hosted SMTP servers.</li>
</ul>
<h4>Override Settings via wp-config.php</h4>
<p>SMTPify supports fixing settings in code by defining constants in <code>wp-config.php</code>. When one of the following constants is defined, the corresponding setting is used instead of the value stored in the admin form:</p>
<ul>
<li><code>SMTPIFY_HOST</code></li>
<li><code>SMTPIFY_PORT</code></li>
<li><code>SMTPIFY_ENCRYPTION</code></li>
<li><code>SMTPIFY_AUTH</code></li>
<li><code>SMTPIFY_USER</code></li>
<li><code>SMTPIFY_PASS</code></li>
<li><code>SMTPIFY_FROM_EMAIL</code></li>
<li><code>SMTPIFY_FROM_NAME</code></li>
<li><code>SMTPIFY_FORCE_FROM</code></li>
</ul>
<p>These definitions must be added manually to <code>wp-config.php</code> before the line that says <code>/* That's all, stop editing! Happy publishing. */</code>.</p>
<p>Example:</p>
<pre><code>php
define( 'SMTPIFY_HOST', 'smtp.example.com' );
define( 'SMTPIFY_PORT', 587 );
define( 'SMTPIFY_ENCRYPTION', 'tls' );
define( 'SMTPIFY_AUTH', true );
define( 'SMTPIFY_USER', 'user@example.com' );
define( 'SMTPIFY_PASS', 'your-smtp-password' );
define( 'SMTPIFY_FROM_EMAIL', 'no-reply@example.com' );
define( 'SMTPIFY_FROM_NAME', 'My Site' );
define( 'SMTPIFY_FORCE_FROM', true );
</code></pre>
<p>When a setting is overridden this way, the field on the plugin settings page is shown as read-only and displays <code>Overridden by ... in wp-config.php.</code></p>
<h4>Test Email</h4>
<p>Use the <strong>Send a Test Email</strong> section at the bottom of the settings page to send a live test to any address. The result, whether a success message or a detailed error from PHPMailer, is shown immediately on the page.</p>
<h4>Mail Error Log</h4>
<p>The <strong>Mail Error Log</strong> section lists the 20 most recent mail failures, each showing the date, recipient, and error message. Use Clear Log to delete all entries.</p>
<h3>Using Gmail as Your SMTP Server</h3>
<p>Gmail requires an <strong>App Password</strong> instead of your regular Google account password. App Passwords are available when two-factor authentication (2FA) is enabled, which is now mandatory for most Google accounts.</p>
<h4>Step 1 — Create an App Password in Google</h4>
<ol>
<li>Sign in to your Google account and go to <a href="https://myaccount.google.com/apppasswords" rel="nofollow ugc">myaccount.google.com/apppasswords</a>.</li>
<li>Enter a name to identify this password (e.g. <code>WordPress</code>) and click <strong>Create</strong>.</li>
<li>Google displays a 16-character password. Copy it now, as it will not be shown again.</li>
</ol>
<p>You can create as many App Passwords as you like under a single Google account. Creating one per environment (production, staging, development) is recommended: if one is compromised, you can revoke it without affecting the others.</p>
<h4>Step 2 — Enter these values on the SMTPify settings page</h4>
<ul>
<li><strong>SMTP Host</strong>: <code>smtp.gmail.com</code></li>
<li><strong>Encryption</strong>: TLS (STARTTLS)</li>
<li><strong>SMTP Port</strong>: <code>587</code></li>
<li><strong>Authentication</strong>: checked</li>
<li><strong>Username</strong>: your full Gmail address (e.g. <code>youraddress@gmail.com</code>)</li>
<li><strong>Password</strong>: the 16-character App Password from Step 1</li>
</ul>
<h4>Step 3 — Send a test email</h4>
<p>Use the <strong>Send a Test Email</strong> section at the bottom of the settings page to confirm that mail is delivered correctly before relying on the configuration in production.</p>
<h4>Notes</h4>
<ul>
<li>Your regular Gmail password will not work; only App Passwords are accepted over SMTP.</li>
<li>An App Password grants SMTP access to anyone who knows it, regardless of which application or server uses it. Store it securely and revoke it immediately at <a href="https://myaccount.google.com/apppasswords" rel="nofollow ugc">myaccount.google.com/apppasswords</a> if you suspect it has been exposed.</li>
</ul>


SMTPify

Routes wp_mail() through your provider's SMTP server. Simple settings page, built-in test tool, nothing else.

Simple SMTP Mailer vs SMTPify