Connect SendGrid for Emails


Connect SendGrid for Emails is a third-party fork of (and a drop-in replacement for) the official SendGrid plugin. This plugin is not endorsed by or affiliated with SendGrid. This plugin connects to an external service (the SendGrid API).

The Connect SendGrid for Emails plugin replaces WordPress’s default wp_mail() function by using either an SMTP or API integration with SendGrid to send outgoing email from your WordPress installation. It also allows you to upload contacts directly to your SendGrid Marketing Campaigns account via a subscription widget.

By using the Connect SendGrid for Emails plugin, you will be able to take advantage of improved deliverability and an expanded feature set, including tracking and analytics, to enhance user engagement on your WordPress installation.

The Subscription Widget

The WordPress Subscription Widget makes it easy for people visiting your WordPress site to subscribe to your marketing emails, such as any newsletters, announcements, or promotional offers you may send. Upon signup, they’ll automatically receive an opt-in email allowing them to confirm their desire to begin receiving your emails. This confirmation constitutes “double opt-in,” a deliverability best practice.


If you are using the Connect SendGrid for Emails plugin in a Multisite environment, you need to Network Activate it. You can then access the settings page on the network dashboard and the configure settings will be used for all sites.

You can enable access for SendGrid settings to each subsite in the Multisite Settings tab. If the checkbox is unchecked then that site will not see the SendGrid settings page and it will use the settings set on the network.
Warning! When you activate SendGrid management for a subsite, that site will not be able to send emails until the admin updates the SendGrid settings on that subsite.

If you already had the plugin installed in a Multisite environment and you update to versions after 1.9.0 you may need to reconfigure your plugin.



  1. PHP version >= 5.6 and <= 7.1. Installing this plugin on PHP versions 5.3 and earlier will cause your website to break. Installation on PHP versions 5.4 and 5.5 will work but it is not recommended.
  2. To send emails through SMTP you need to install also the ‘Swift Mailer’ plugin.
  3. If wp_mail() function has been declared by another plugin that you have installed, you won’t be able to use the Connect SendGrid for Emails plugin

To upload the Connect SendGrid for Emails plugin .ZIP file:

  1. Upload the WordPress SendGrid Plugin to the /wp-contents/plugins/ folder.
  2. Activate the plugin from the “Plugins” menu in WordPress.
  3. Create a SendGrid account at
  4. Navigate to “Settings” -> “SendGrid Settings” and enter your SendGrid credentials.

To auto install the Connect SendGrid for Emails plugin from the WordPress admin:

  1. Navigate to “Plugins” -> “Add New”
  2. Search for “Connect SendGrid for Emails” and click “Install Now” for the “Connect SendGrid for Emails” listing.
  3. Activate the plugin from the “Plugins” menu in WordPress, or from the plugin installation screen.
  4. Create a SendGrid account at
  5. Navigate to “Settings” -> “SendGrid Settings” and enter your SendGrid credentials

For Multisite:

  1. Navigate to “My Sites” -> “Network Admin” -> “Plugins”
  2. Click on “Add New”
  3. Search for “Connect SendGrid for Emails” and click “Install Now” for the “Connect SendGrid for Emails” listing.
  4. Network Activate the plugin from the “Plugins” menu in WordPress, or from the plugin installation screen.
  5. Create a SendGrid account at
  6. Navigate to “My Sites” -> “Network Admin” -> “Dashboard”
  7. Click on the “SendGrid Settings” item in the menu on the left and enter your SendGrid credentials.

Global Settings

SendGrid settings can optionally be defined as global variables (wp-config.php):

  1. Set the API key. You need to make sure you set the Mail Send permissions to FULL ACCESS, Stats to READ ACCESS and Template Engine to READ or FULL ACCESS when you created the api key on SendGrid side, so you can send emails and see statistics on wordpress):

    • API key: define(‘SENDGRID_API_KEY’, ‘sendgrid_api_key’);
  2. Set email related settings:

    • Send method (‘api’ or ‘smtp’): define(‘SENDGRID_SEND_METHOD’, ‘api’);
    • From name: define(‘SENDGRID_FROM_NAME’, ‘Example Name’);
    • From email: define(‘SENDGRID_FROM_EMAIL’, ‘’);
    • Reply to email: define(‘SENDGRID_REPLY_TO’, ‘’);
    • Categories: define(‘SENDGRID_CATEGORIES’, ‘category_1,category_2’);
    • Template: define(‘SENDGRID_TEMPLATE’, ‘templateID’);
    • Content-type: define(‘SENDGRID_CONTENT_TYPE’, ‘html’);
    • Unsubscribe Group: define(‘SENDGRID_UNSUBSCRIBE_GROUP’, ‘unsubscribeGroupId’);
  3. Set widget related settings:

    • Marketing Campaigns API key: define(‘SENDGRID_MC_API_KEY’, ‘sendgrid_mc_api_key’);
    • Use the same authentication as for sending emails (‘true’ or ‘false’): define(‘SENDGRID_MC_OPT_USE_TRANSACTIONAL’, ‘false’);
    • The contact list ID: define(‘SENDGRID_MC_LIST_ID’, ‘listID’);
    • Display the first and last name fields (‘true’ or ‘false’): define(‘SENDGRID_MC_OPT_INCL_FNAME_LNAME’, ‘true’);
    • First and last name fields are required (‘true’ or ‘false’): define(‘SENDGRID_MC_OPT_REQ_FNAME_LNAME’, ‘true’);
    • Signup confirmation email subject: define(‘SENDGRID_MC_SIGNUP_EMAIL_SUBJECT’, ‘Confirm subscription’);
    • Signup confirmation email content: define(‘SENDGRID_MC_SIGNUP_EMAIL_CONTENT’, ‘<a href=”%confirmation_link%”>click here</a>’);
    • Signup confirmation page ID: define(‘SENDGRID_MC_SIGNUP_CONFIRMATION_PAGE’, ‘page_id’);
  4. Other configuration options:

    • Set a custom timeout for API requests to SendGrid in seconds: define(‘SENDGRID_REQUEST_TIMEOUT’, 10);


Use HTML content type for a single email:

add_filter('wp_mail_content_type', 'set_html_content_type');

// Send the email

remove_filter('wp_mail_content_type', 'set_html_content_type');

Change the email contents for all emails before they are sent:

function change_content( $message, $content_type ) {
    if ( 'text/plain' == $content_type ) {
      $message = $message . ' will be sent as text ' ;
    } else {
      $message = $message . ' will be sent as text and HTML ';

    return $message;

add_filter( 'sendgrid_override_template', 'change_content' );

Changing the text content of all emails before they are sent:

function change_sendgrid_text_email( $message ) {
    return $message . ' changed by way of text filter ';

add_filter( 'sendgrid_mail_text', 'change_sendgrid_text_email' );

Changing the HTML content of all emails before they are sent:

function change_sendgrid_html_email( $message ) {
    return $message . ' changed by way of html filter ';

add_filter( 'sendgrid_mail_html', 'change_sendgrid_html_email' );

Note that all HTML emails sent through our plugin also contain the HTML body in the text part and that content will pass through the “sendgrid_mail_text” filter as well.


What PHP versions are supported ?

Plugin versions 1.11.x were tested and confirmed to work on PHP 5.4, 5.5, 5.6, 7.0, 7.1. It DOES NOT work on PHP 5.3 and earlier.

Plugin versions 1.10.x were tested and confirmed to work on PHP 5.3, 5.4, 5.5 and 5.6. It DOES NOT work on PHP 7.0 and later.

What credentials do I need to add on settings page ?

Create a SendGrid account at and generate a new API key on

How can I define a plugin setting to be used for all sites ?

Add it into your wp-config.php file. Example: define('SENDGRID_API_KEY', 'your_api_key');.

How to use Connect SendGrid for Emails with WP Better Emails plugin ?

If you have WP Better Emails plugin installed and you want to use the template defined here instead of the Connect SendGrid for Emails template you can add the following code in your functions.php file from your theme:

function use_wpbe_template( $message, $content_type ) {
    global $wp_better_emails;
    if ( 'text/plain' == $content_type ) {
      $message = $wp_better_emails->process_email_text( $message );
    } else {
      $message = $wp_better_emails->process_email_html( $message );

    return $message;
add_filter( 'sendgrid_override_template', 'use_wpbe_template', 10, 2 );

Using the default templates from WP Better Emails will cause all emails to be sent as HTML (i.e. text/html content-type). In order to send emails as plain text (i.e. text/plain content-type) you should remove the HTML Template from WP Better Emails settings page. This is can be done by removing the ‘%content%’ tag from the HTML template.

Why are my emails sent as HTML instead of plain text ?

For a detailed explanation see this page:

Will contacts from the widget be uploaded to Marketing Campaigns or Legacy Newsletter?

The contacts will only be uploaded to Marketing Campaigns.

What permissions should my API keys have ?

For the API Key used for sending emails (the General tab):
– Full Access to Mail Send.
– Read Access to Stats.
– Read Access to Supressions > Unsubscribe Groups.
– Read Access to Template Engine.
For the API Key used for contact upload (the Subscription Widget tab):
– Full Access to Marketing Campaigns.

Can I disable the opt-in email ?

No. SendGrid’s Email Policy requires all email addressing being sent to by SendGrid customers be confirmed opt-in addresses.

Can I change the content of the emails before they are sent ?

Yes. You must add a filter that does that. You need to declare a function that takes the content of the email as argument and then call add_filter() with the name “sendgrid_mail_text” or “sendgrid_mail_html”, depending on what part of the email you want to change.

If you want to change the text content of all the emails before they are sent you can do it like this :

function change_sendgrid_text_email( $message ) {
    return $message . ' changed by way of text filter ';

add_filter( 'sendgrid_mail_text', 'change_sendgrid_text_email' );

If you want to change HTML content of all the emails before they are sent you can do it like this :

function change_sendgrid_html_email( $message ) {
    return $message . ' changed by way of html filter ';

add_filter( 'sendgrid_mail_html', 'change_sendgrid_html_email' );

Note that what is changed depends of the content-type that you have set in the settings page or overwritten by way of filter. For “text/plain” only the text part is overwritten by the filter. For “text/html” both the text and the HTML filters are called.

The code snippets above are usually added in the functions.php file of your theme.

Can I use this plugin with BuddyPress ?

Yes. Our plugin required special integration with BuddyPress and it’s regularly tested to ensure it behaves as expected. If you have noticed issues caused by installing this plugin along with BuddyPress, you can add the following line to your wp-config.php to disable it :


If you’re trying to send plaintext emails using BuddyPress, keep in mind that by default the whitespace content of those emails is normalized.

That means that some newlines might be missing if you expect them to be there.

To disable this functionality, you need to add the following line in your wp-config.php file:


Can I use shortcodes to customize the subscription confirmation page ?

Yes. You need to create custom page and select it from the settings page. You can place any of these shortcodes in the body of that page. Here’s an example :

Hi [sendgridSubscriptionFirstName] [sendgridSubscriptionLastName],
Your email address : [sendgridSubscriptionEmail] has been successfully added.
You'll hear from us soon!

You need to enable the use of the First Name and Last Name fields from the settings page in order to use the shortcodes for them.

Does this plugin support Multisite?

Yes. This plugin has basic Multisite support. You need to Network Activate this plugin.

The settings for all sites in the network can be configured only by the Network Admin in the Network Admin Dashboard.

Since 1.10.5 the Network Admin can delegate the configuration for each subsite to their respective owners. This will allow any subsite to use it’s own SendGrid Plugin configuration.

How can I further customize my emails?

When calling the wp_mail() function you can send a SendGrid PHP email object in the headers argument.

Here is an example:

$email = new SendGrid\Email();
    ->setHtml('<strong>Hello World!</strong>')

wp_mail('', 'Subject goes here', 'Message goes here', $email);

You can find more examples here:

My server is slow. Can I increase the timeout for API requests?

Yes. You can define a constant in your wp-config.php file like this:


The value is in seconds, this means that API requests will wait 10 seconds for a reponse from the SendGrid API server until timing out.


2023(e)ko abuztuaren 17(a)
I spent long hours looking for a solution to send emails on my restricted hosting account. Out of despair, I tried all the plugins in the repository that modified the wp_mail() function (incl. plugins with millions of installations) but none of the commercial plugins out there come even closer to what this simple but effective plugin provides! I was able to connect to sendgrid for seconds, just adding api key and sender's address. Plugin supports multisite (free versions of other commercial plugins lacking this) and had all the options I needed, e.g. not showing the plugin settings on a single instance.
2022(e)ko azaroaren 15(a)
This plugin is good and the settings are so simple and easy to use and most important working as expected.
Irakurri 2 berrikuspenak

Laguntzaileak eta Garatzaileak

“Connect SendGrid for Emails” software librea da. Ondoko pertsonek egin dizkiote ekarpenak plugin honi.


Aldaketen loga


Fix: HTML code showing in labels for required fields in the subscription widget


Fix: The Subscription Widget was no longer working (and settings page not accepting API key) due to changes in the SendGrid API

Fix: (UX) Don’t auto-submit settings forms when entering API key

Fix: Email subject field in Subscription Widget settings was not populated correctly

Fix: Make Subscription Widget success/error pages more compatible with various theme(s)

Fix: PHP warnings when subscribing via the subscription widget
= 1.11.10
* Remove admin notice about widget due to critical error when dismissing

1.11.9 (first Aspen Grove Studios release)

  • Fix security vulnerability CVE-2021-34629 (users without the manage_options capability can still call an ajax method to retrieve statistics on a multisite main site)
  • Add HTML escaping and text domain to translated text
  • Remove deprecated contextual_help hook
  • Miscellaneous minor changes


  • Updated the plugin description to direct users to for questions.
  • Updated the “tested up to” field to confirm the latest version of the plugin wordes with the latest version of wordpress.


  • Added a configuration parameter of API request timeout in seconds
  • Fixed an issue that made the HTML subscription emails break links


  • Added a feature flag to disable whitespace normalization in BuddyPress plaintext emails
  • Fixed an issue where the from name and email subjects would incorrectly display the ampersand symbol


  • Fixed a potential stored XSS issue on the backend settings form
  • Fixed a potential CSRF issue on the backend settings form


  • Fixed an issue where TO field recipients could not see each other in the email header


  • Fixed an issue where the send test form was displayed when no API key was set
  • Fixed an issue where the subscription test form was not displayed for the default contact list
  • Fixed an issue where the virtual pages for Subscription errors was not displayed
  • Fixed an issue where there was no notification for option update on the Multisite settings page
  • Fixed an issue where there was no notification when an API key was not set on the General tab when there was one on the Subscription Widget tab


  • Relaxed PHP requirement to at least version 5.4.


  • Confirmed compatibility with PHP 7 and 7.1
  • Removed some legacy code that caused warnings in PHP 7
  • Fixed issue where the statistics page would show up in menu even if the API key did not have stats permissions


  • BREAKING CHANGE: DO NOT UPGRADE IF YOU USE PHP <= 5.3. Only PHP 5.4 and later versions are supported.
  • BREAKING CHANGE: Username & Password is no longer supported. Change your settings to use an API Key before updating
  • API Mail Send was changed to use the V3 SendGrid API
  • Emails sent with the V2 Email Object will now be translated to V3
  • BREAKING CHANGE: The date parameter on the V2 object is no longer supported
  • BREAKING CHANGE: When using the V2 object with SMTPAPI Tos, the BCC and CCs will only be applied to the first address


  • Added pagination on multisite settings page
  • Fixed an FAQ link
  • Changed a class method to protected for extensibility (user contribution)
  • Added some CSS classes for subscription widget (user contribution)
  • Added warning when API Key doesn’t have statistics permissions
  • The statistics page will not show up in menu or dashboard when API key does not have stats permissions


  • Fixed an XSS vulnerability in the settings forms that would allow other admins to inject scripts


  • Add port 2525 for SMTP
  • Use cache for stats widget on dashboard


  • Fixed logos and fonts on Stats page


  • Added settings page on multisite to give access to self manage SendGrid plugin to each subsite


  • Set transient token for Marketing Campaign in database


  • Add option to configure text version using setText() function from the header
  • Tested up to 4.7


  • Add options to configure subscription widget form (labels, padding)


  • Fixed a javascript error and a PHP warning


  • Added basic Multisite functionality
  • WARNING: Multisite users need to network activate this plugin and reconfigure it.
  • Fixed an issue where other users would see the SendGrid statistics widget on the dashboard.


  • Fixed an issue with the Reply-To field


  • Added Unsubscribe Group option
  • Improved email validation


  • Added BuddyPress integration
  • MC API Key is now saved on focusout
  • Added posibility of using plain text template for subscription confirmation email
  • Added posibility of adding shortcodes to subscription confirmation pages


  • Improved response time on admin dashboard


  • Added filters that allow the change of text or HTML content of all emails before they are sent
  • Fixed an issue with the widget admin notice


  • Added the SendGrid Subscription Widget
  • The settings page now has tabs to separate the configuration of general settings from the widget settings
  • Fixed an issue where a ‘gzinflate()’ warning was displayed in Query Monitor for each plugin request
  • Fixed an issue where the API Key would be deleted from the db if it was set in wp-config


  • Update SendGrid logos


  • Added possibility to override the email template


  • Added SendGrid\Email() for $header
  • Fix Send Test form not being displayed issue


  • Updated validation for email addresses in the headers field of the send test email form
  • Add ability to have and individual email sent to each recipient by setting x-smtpapi-to in headers


  • Fixed an issue with the reset password email from WordPress
  • Updated validation for email addresses
  • Fixed an issue where some errors were not displayed on the settings page
  • Add substitutions functionality


  • Fixed some failing requests during API Key checks
  • Fixed an error that appeared on fresh installs regarding invalid port setting


  • Add global config for content-type
  • Validate send_method and port set in config file
  • Be able to define categories for which you would like to see your stats


  • Check your credentials after updating, you might need to reenter your credentials
  • Fixed mcrypt library depencency issue


  • BREAKING CHANGE: Don’t make update if you don’t have mcrypt php library enabled
  • Fixed a timeout issue from version 1.7.0


  • BREAKING CHANGE : wp_mail() now returns only true/false to mirror the return values of the original wp_mail(). If you have written something custom in your function.php that depends on the old behavior of the wp_mail() you should check your code to make sure it will still work right with boolean as return value instead of array
  • BREAKING CHANGE: Don’t make update if you don’t have mcrypt php library enabled
  • Added the possibility of setting the api key or username/password empty
  • Added the possibility of selecting the authentication method
  • Removed dependency on cURL, now all API requests are made through WordPress
  • Sending mail via SMTP now supports API keys
  • Security improvements
  • Refactored old code


  • Add categories in headers, add errror message on statistics page if API key is not having permissions


  • Update api_key validation


  • Ability to use email templates, fix category statistics, display sender test form if we only have sending errors


  • Remove $plugin variable to avoid conflict with other plugins


  • Add configurable port number for SMTP method, Specify full path for sendgrid php library, Fix special characters and new lines issues


  • Add support for toName in API method, Add required Text Domain


  • Update Smtp class name to avoid conflicts


  • Add Api Keys for authentication, use the last version of Sendgrid library:


  • Add unique arguments


  • Fix setTo method in SMTP option, update documentation, add link to SendGrid portal


  • Updated the plugin to use the last version of Sendgrid library:


  • Fix attachments issue


  • Fix urlencoded username issue


  • Fix wp_remote issue


  • Updated the plugin to use the last version of Sendgrid library:


  • Added constants for SendGrid settings


  • Fix changelog order in readme file


  • Fix unicode filename for icon-128×128.png image


  • Update plugin logo, description, screenshots on installation page


  • Added SendGrid Statistics for the categories added in the SendGrid Settings Page


  • Added support to set additional categories


  • Fix warnings for static method, add notice for php version < 5.3.0, refactor plugin code


  • Fix URL for loading image



  • Added support for WordPress 3.8, fixed visual issues for WordPress 3.7


  • Fix errors: set_html_content_type error, WP_DEBUG enabled notice, Reply-To header is overwritten by default option


  • Added statistics for emails sent through WordPress plugin


  • Fix missing argument warning message


  • Fix display for october charts


  • Added default category on sending


  • Added SendGrid Statistics


  • Fixed issue: Add error message when PHP-curl extension is not enabled.