How to check if you have TLS 1.2 support in your server

As you know, on May 31, 2018 MailChimp will be retiring support for TLS versions 1.0 and 1.1

Try this tinny code to make sure that your server has the correct openssl lib

 $ch = curl_init();
 curl_setopt($ch, CURLOPT_URL, "https://www.howsmyssl.com/a/check");
 curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
 $response = curl_exec($ch);
 curl_close($ch);
 $tlsVer = json_decode($response, true);
 echo "Your TLS version is: " . ( $tlsVer['tls_version'] ? $tlsVer['tls_version'] : 'no TLS support' ) . "\n";

If the result is not Your TLS version is: TLS 1.2 You must update your openssl lib

If you are using RedHat Enterprise Linux, or CentOS

• version 6 and higher, you will need to take package updates. You can do this by running sudo yum update openssl libcurl, and restarting your web server.
• version 5, you will need to upgrade to at least Red Hat Enterprise Linux 6. We recommend rebuilding your server, as the upgrade process is risky.

If you are using Ubuntu

• 12.04 LTS (Precise) and higher, you will need to take package updates. You can do this by running sudo apt-get update && sudo apt-get install --only-upgrade openssl, and then restarting your web server. You may also need to update your libssl. You can update this by running sudo apt-get update && sudo apt-get install --only-upgrade libssl-dev.
• 10.10 (Maverick), 11.04 (Natty), or 11.10 (Oneiric), you will need to upgrade to at least Ubuntu 12.04 (Precise). The easiest way to do this is to rebuild your server, as upgrading from these non-LTS Ubuntu versions is not supported.
• 10.04 LTS (Lucid), you will need to upgrade to at least Ubuntu 12.04 (Precise). We recommend rebuilding your server, as the upgrade process is risky.