As some people are confused about the name:
> According to Canfield, he initially intended to use Cock.li only as his own personal email address. “It wasn’t until November [2013] that I posted the address on 4chan, and someone responded and said ‘I would love an email address there,’” Canfield said.
> Other emails offered through Cock.li include horsefucker.org and goat.si—as well as other more vulgar domains we’ll refrain from printing here[...]
– https://www.vice.com/en/article/the-story-of-cockli-the-site...
One of the most well known domain of them is nuke.africa although I don't know if email registration is still possible under that domain.
Cock.li is the edge lord of fringe email providers and was down for quite some time for reasons I did not care to get into.
