Sendgrid links in email produce Your connection is not private error in browser

Question

Rails 5.2 SendGrid Heroku App

I have a link in an email to view a report. The links work perfectly in development.

However, when SendGrid sends the emails in production and I click on the link in the email I get the following error in the browser:

Your connection is not private
Attackers might be trying to steal your information from myapp.heroku.com (for example, passwords, messages, or credit cards). Learn more
NET::ERR_CERT_COMMON_NAME_INVALID

In my production config I have the following:

  # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
  config.force_ssl = true

config.action_mailer.default_url_options = { host: 'https://provenwordapp.heroku.com' }

From other SO users the above worked for them. However, it's not working for me.

Any help appreciated.

Answer 1

Have you enabled SSL Click Tracking on your SendGrid account?

That error is generally because you're moving from an HTTPS > HTTP connection, or vice versa. If you have SendGrid's Click Tracking enabled, but don't have SSL enabled, their tracked links will be http://, even though your base link is https://.

Answer 2

I have found the problem.

I did not use the correct URL for my app on Heroku.

config.action_mailer.default_url_options = { host: 'https://provenword.herokuapp.com' }

I had written heroku.com instead of herokuapp.com

Thanks to everyone for their assistance.