Submit new public archives immeditaly to search engines for indexing
When a new mail is archived by hyperkitty and it is in a public archive, hyperkitty shall signal search engines to index that file (immediately). Google, Bing and Yandex support a protocol for informing them, when a new webpage is created (modified and deleted).
Implement in Hyperkitty support for these communications with these search engines. (Naver likely also has a protocol for this, but it is described in Korean and I do not understand it).