Feel free to add nfrelay.app , read-only aggregator relay. It has already spam filter to handle most spam like RplyFamily and imposter 🙂
Discussion
What you mean read-only? But how to reply and post?
You can freely use any other relay to write for example relay.damus.io nos.lol nostr.wine or other major relays. nfrelay.app will fetch/mirror automatically from other relays your notes/events and will store the event.
But how could I connect to your relay for reduce spam, and still write to major relays? Everybody tells me to disconnect from majors. How does it work?
What is your nostr clients? If it is Amethyst you can set it with something like this

"Down arrow" icon meaning is to set relay as "Read" relay while "Up arrow" is to set as "Write". You can set both active or just one arrow icon.
Example:
nos.lol - write and read
nostr.wine - read
wot.utxo.one - write and read
nfrelay.app - read
relay.damus.io write
and etc.
Yeah, I use Amethyst. Didn't know that it can be tuned like that. Thanks, will try!
Welcome. Yes, it seems like easter feature 😅
You can also check where the spam from small relay icon beside of notes/post
Cool, thanks, Rif'at. Followed!