SMTP.com

<p><a href="https://smtp.com" rel="nofollow ugc">SMTP.com</a> was the first company to provide email delivery at scale for customers unsatisfied with traditional sending methods. With over 22 years of email delivery success, SMTP.com is the trusted transactional and email relay provider for over 100,000 businesses worldwide. This WordPress integration for SMTP.com enables you to send and track your emails seamlessly.</p>
<p>Don’t worry about maintaining your email server or taking care of its IP reputation, forget about dealing with ISPs like Gmail, Yahoo or Microsoft in attempting to understand why your email isn’t reaching its destination. SMTP.com manages all this on your behalf. Simply create a SMTP.com account to <a href="https://registration.smtp.com/?afid=wpplugin" rel="nofollow ugc">get started</a> and set up this plugin. Although this plugin is free you will need a paid subscription with SMTP.com to send emails from your WordPress site.</p>
<p>You can send emails from your WordPress site using the SMTP.com API or the standard SMTP protocol. Our plugin will suggest the best way for you to send email even if your provider has restricted access to outbound internet ports. Either way, SMTP.com will still ensure your email gets delivered.</p>
<p>Another useful feature provided with our WordPress plugin is the ability to track your email delivery from within the plugin itself. See the results of your recent sends to ensure successful delivery or identify the reason why your particular email hasn’t been delivered.</p>



Didn't work with the API key, but managed with the login information.


Good

SMTP.com is a powerful and reliable SMTP delivery service that enables you to send and track high volume emails effortlessly.

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.

SMTP.com vs SMTPify