Interesting distinction.    Campaigns originating from Constant Contact customers embed images from Akamai enpoints host behind the CNAME files.contactcontact.com, but campaigns from Constant Contact themselves use the CNAME click.c.constantcontact.com to store images.   The TLS configuration behind click.c.constantcontact.com has much broader platform support than files.constantcontact.com.   See https://www.ssllabs.com/ssltest/analyze.html?d=click.c.constantcontact.com.   Can the cipher configuration at click.c.constantcontact.com be configured at files.constantcontact.com? ... View more

See https://www.ssllabs.com/ssltest/analyze.html?d=files.constantcontact.com&s=184.25.254.11&latest.   The cipher list used by the Akamai endpoints publishing the image URLs for Constant Contact campaigns has changed recently resulting in older Windows and MacOS implementations being incompatible with TLS negoiation requirements to render images embedded in Constant Contact campaigns.   Can the previous cipher list be rolled back to restore compatibility with these older systems?   There are still very common, and the additional security gained by removing the older ciphers really isn't warranted for this application. ... View more