Error: SendGrid WordPress email wasn't sent

What's Causing This Error

WordPress not sending emails is a common problem. There are a few possible causes for your WordPress emails not being sent:

• The most typical explanation is that your emails appear to be spam. When your web server creates an email, it merely creates the headers necessary for basic PHP mail delivery (). The standard PHP mail() function does not include any authentication to ensure that the message is genuine. You may fix this by using WP Mail SMTP.
• PHP mail() has been disallowed by your site hosting provider. Many web hosts simply disable PHP for mailing due to inherent security issues with PHP mail(), preventing your WordPress site from sending messages at all. If you use Amazon EC2 or Lightsail, you might run into this issue. Because WP Mail SMTP uses SMTP rather than PHP for email delivery, you'll be able to get around this.
• You're using localhost. If you build your website locally, your emails will most likely fail. WP Mail SMTP will address WordPress's inability to send an email on localhost, allowing you to receive WordPress notifications in the same way that a live site would.

Here's How To Resolve It

• You'll need to install WP Mail SMTP on your WordPress site first. WP Mail SMTP is a WordPress plugin that modifies the wp mail() PHP mailer function to use SMTP instead of PHP.
• Activate email logging. By default, two options will be activated. They are as follows:
• Deliverability of emails.
• Tracking errors.