Recently i buy dedicated ssl also i use full (strict) for my website, i use it to will be secure but now my mail services (Yandex) is not function it’s says https://mail. anhdoge .net | 526: Invalid Certificate.
CNAME of mail alias domain. mail. yandex .net (CDN is on) but if i will removed https:// to http and turn off CDN on domain .mail. yandex .net certificate of my site is not worked.