Does the recipient also need to have similar client?
Those of you that are seeing reports and notes from a new DM Reporter bot need not fear the reports. They again are a form of education. This is how we grow and improve.
These bots are telling you that the client that you're using to DM others is leaking metadata such as who you spoke to and when you spoke to them. The conversation itself is encrypted.
How can you stop this from happening?
You need to switch to a client that uses better DM technology such as Amethyst, Snort, Iris, etc. or just use nostr:nprofile1qqs9ajjs5p904ml92evlkayppdpx2n3zdrq6ejnw2wqphxrzmd62swspzemhxue69uhhyetvv9ujuvrcvd5xzapwvdhk6qgdwaehxw309aukzcn49ekk2qghwaehxw309aex2mrp0yh8x6tpd4ehgu3wvdhk6ynf30t for all of your DM needs.
Discussion
Clients must support the same NIPs. For encrypted DMs/Chats/Groups in 0xChat: NIP 04, 17, 29, 44, 100. https://github.com/0xchat-app
+NIP 101
What about DM inbox and outbox relays?
There's not much of free relays for DMs . Not all clients support specific DM relay setting. Anyway I believe most of us using free DM relays like auth.nostr1.com. 0xChat have it's own relay.0xchat.com (you can add it to your client easily). From my 0xChat app: "If not set, [DMs] will be sent to the general relay by default".