Really? auto-delete from the keychat inbox relay?
nostr:npub10npj3gydmv40m70ehemmal6vsdyfl7tewgvz043g54p0x23y0s8qzztl5h has
wss://auth.nostr1.com
but i haven't played around with it much as I've been pretty happy with DMs over KeyChat (which does have an auto delete setting for messages).
Discussion
idk how they work it but it is there to configure in the settings