BaiatuLuTata

This plugin overrides the default WordPress email sending function with SendGrid’s Mail Send API.
Key Features:
<ul>
<li>Toggle Email Override for SendGrid on/off</li>
<li>Enter your SendGrid API key</li>
<li>Customize the “From” email and name</li>
<li>Send a test email directly from the settings page</li>
<li>Clean and native WordPress admin UI</li>
</ul>
<h3>External Services</h3>
This plugin integrates with the <a href="https://www.sendgrid.com/" rel="nofollow ugc">SendGrid</a> email delivery service to send outgoing emails via its API instead of the default <code>wp_mail()</code> function.
When enabled, the plugin communicates with the following SendGrid API endpoint: https://api.sendgrid.com/v3/mail/send
Data sent to SendGrid includes: 
– Sender name and email 
– Recipient email(s) 
– Email subject 
– Message body (text or HTML) 
– Optional headers (Cc, Bcc)
The plugin requires a valid SendGrid API key to function. This credential is stored in your WordPress database and used only to authenticate API requests to SendGrid.
Privacy Notice: 
By using this plugin, you agree to SendGrid’s <a href="https://www.sendgrid.com/terms-of-service/" rel="nofollow ugc">Terms of Service</a> and <a href="https://www.sendgrid.com/privacy-policy/" rel="nofollow ugc">Privacy Policy</a>. Ensure your use of SendGrid complies with local privacy laws and your own data protection policies.

Email Override for SendGrid

Replaces WordPress wp_mail() with SendGrid's API. Adds a settings page to manage API key, sender info, and test email functionality.

Surbma

CherryPick Studios

This plugin is created especially for Multisite Networks. You can define all variables in the wp-config.php file and it will be valid for all sites in a Multisite. So this is not for a site-by-site configuration plugin. You can install it on a single WordPress install also and it will work perfectly. But if you install it in a Multisite Network, you can only network activate it!
This plugin is working with all SMTP servers and services, like Mailgun, SendGrid, Mandrill, Amazon SES and others.
Required variables:
<ul>
<li><code>SURBMA_SMTP_HOST</code> – External SMTP server.</li>
<li><code>SURBMA_SMTP_USER</code> – User for the SMTP account.</li>
<li><code>SURBMA_SMTP_PASSWORD</code> – Password for the SMTP account.</li>
</ul>
Optional variables:
<ul>
<li><code>SURBMA_SMTP_PORT</code> – Port number for the SMTP server.</li>
<li><code>SURBMA_SMTP_SECURE</code> – Choose SSL or TLS, if necessary for your SMTP server.</li>
<li><code>SURBMA_SMTP_FROM</code> – From email address for all outgoing emails.</li>
<li><code>SURBMA_SMTP_FROMNAME</code> – From name for all outgoing emails.</li>
</ul>
Example configuration:
<pre><code> define('SURBMA_SMTP_HOST','smtp.mailgun.org');
 define('SURBMA_SMTP_USER','postmaster@surbma.com');
 define('SURBMA_SMTP_PASSWORD','bb2b************************4133');
</code></pre>
You can put these lines everywhere before the line, that says: “That’s It. Pencils down”
Do you want to contribute or help improving this plugin?
You can find it on GitHub: <a href="https://github.com/Surbma/surbma-smtp" rel="nofollow ugc">https://github.com/Surbma/surbma-smtp</a>
You can find my other plugins and projects on GitHub:
<a href="https://github.com/Surbma" rel="nofollow ugc">https://github.com/Surbma</a>
Please feel free to contribute, help or recommend any new features for my plugins, themes and other projects.
Do you want to know more about me?
Visit my webpage: <a href="http://surbma.com/" rel="nofollow ugc">Surbma.com</a>

Surbma | SMTP

External SMTP mail configuration via global variables in wp-config.php.

Email Override for SendGrid vs Surbma | SMTP