Due to changes in security, it may be necessary to update a site to use TLS 1.2 for outbound connections. Most notably for a payment gateway. Please note this only affects outbound connections and is not related to a SSL certificate that may be installed for the site.
For outbound TLS 1.2, a site will need to be using at least Framework 4.5. If a site is using an older Framework, it will need to be updated. However, only Framework 4.7 (not currently supported on Windows Azure Pack) will use TLS 1.2 by default. If a site is using Framework 4.5 or 4.6, bootstrapping code is required to force TLS 1.2. The following stackoverflow.com article provides an overview of the code update if the Framework version cannot be updated, instead: https://stackoverflow.com/a/28333370
PHP / cURL
For PHP, TLS 1.2 support is dependent on the version of PHP set for the site. Which should be set to 5.5 or newer in the Everleap Control Panel.
Everleap Control Panel > Sites > Manage (applicable domain if multi-site) > Settings > PHP
To test TLS 1.2, the script in zcurl.zip may be used: zcurl.zip