The Constant Contact API, managed by TIBCO’s Mashery, will no longer support TLS v1.0 or v1.1 when establishing secure connections as of September 30th, 2018. We recommend updating your integration to TLS version v1.2 to comply with security practices outlined by the Payment Card Industry (PCI) Security Standard Council.
Please visit our Tech Blog to read our full article.
I'm using the only PHP library listed on your site: https://github.com/constantcontact/php-sdk. I've also been listed as a developer account not running through TLS v1.2 as noted in your post.
Is there a solution for people like me?
Our SDKs are libraries that make it easy for you to make calls to our API. The calls themselves are run from your server with your own framework, so there is no update needed to the SDK directly. Because each web server and application is different, I'm not able to provide you with specific directions on how to make sure everything on your server is up to date. I would recommend reaching out to your hosting provider for detailed steps on how to check or upgrade your TLS compatibility.
Tier II API Support Engineer