Before donating, you may want to consider that the guy operating this service is not just known for operating anonymous email (something I can sympathize with), but also for racist jokes.
Gosh! Thank god you told me! I was going to use cock.li which has email domains such as: cumallover.me, dicksinhisan.us, horsefucker.org, dicksinmyan.us. But now that I know the owner has made racist jokes, which we all know that only bad people do, I'll certainly have nothing to do with this service!
We cannot joke about serious things like society problems, economy, death, relationships and politics - this is serious business only!
(/s in case anyone is dense enough to not get it)