Let users who don't have their dms open see that someone messaged them

Please make a feature like the Instagram dm system. If you dm a user who does not have their dms open please show them the message so they know someone tried to reach out! They can then manually accept or deny that request. Cause right now it is flat out not possible to reach someone that isn't on a server with you anymore who you're not friends with if the dms aren't open. Also it always makes me feel really bad if I talked to someone about a commission for example afterwards they leave a server or remove as friend and I can't ask them for anything further and it just feels like I've been blocked. It just makes me feel sad honestly.. This would mean a lot to me. Thank you!