SSL operation failed with code 1. OpenSSL Error messages: error:1416F086:

Hi there @bvallance,

Thanks for reaching out! It looks like you have an issue with certificate verification on your server. Please check out this guide for more information: https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting#certificate-verification-failure.

Unfortunately, from our end, we’re not able to provide assistance with the troubleshooting and fixing steps, however, when you get a chance, could you please follow up with your hosting support and ask them to look into the issue once more? You can provide them with the error I shared above. They should be able to resolve the issue.

I apologize that we can’t provide an exact solution to this, but I hope the suggestion above could help point you in the right direction.

In case it helps to share, please note that the Other SMTP mailer does not use a dedicated API, which can lead to potential errors based on your website hosting settings. In cases where ongoing issues arise while using the Other SMTP mailer, we generally recommend switching to a transactional mailer option.

Transactional Mailers

Transactional email service providers such as our #1 recommended mailer, SendLayer (https://a.supportally.com/i/6Le9e8), are perfect for sending emails from your WordPress site. If it’s contact form notifications or e-commerce emails, they will deliver them quickly and reliably.

Brevo (formerly Sendinblue), SMTP.com, SendGrid, and Mailgun are also transactional email service providers if you’d like to consider your options.

Transactional mailers also allow you to send emails with custom ‘From Email’ specific to your domain (examples: [email protected], [email protected]).

Google & Outlook Mailers

If you already have a paid plan for Google Workspace (formerly G Suite) or Outlook, I’d recommend using these mailers to send emails.

If you’d like to check out more details on the mailers mentioned above or any others you may be interested in, you can see our complete guide here: https://wpmailsmtp.com/docs/a-complete-guide-to-wp-mail-smtp-mailers/.

I hope that helps! Have a great day! ??

Thanks for your response. After a long call with my hosting company I think the issue is with my development environment Apache web server certificate. Here’s my DEV environment:

• WAMPSERVER (Apache web server, MariaDB, & PHP) on a laptop in my office
• I develop my WordPress websites in my DEV environment. I then upload them to my hosting server as staging websites for client review
• The WP Mail SMTP plugin was working in my DEV environment until 11-8-2024.
• I have updated the WP Mail SMTP plugin to the latest version – no change, still getting the SMTP connection error in my original post

I have WP Mail SMTP configured to send mail through my hosting provider’s server using TLS on port 587. I’m under the impression that the certificate validation problem is with my hosting computer. Am I correct about that, OR is the certificate validation problem with my DEV environment Apache server? I am using a self-signed CA Certificate in my Apache server that includes the domain name of my dev environment. Is the self-signed certificate on my Apache server my problem?

I found the problem. The issue was Norton 360 (the antivirus program). I disabled Auto-Protect, which in my past experience with Norton 360 disabled all protection. But not now. Disabling Auto-Protect still leaves some settings active. What causes the issue I reported above was the Norton 360 outbound email scanning setting. As soon as I disabled it WP Mail SMTP worked perfectly!