Hi, Vikram

While there's not a way to create a "read-only" user, you can create a user, then share their Inbox with others. For each person or group you share that Inbox with, you can set their permissions as "read-only". That will make an Inbox folder appear in their folder list, and they can see emails in that Inbox, but they can't interact with them in any way. That should accomplish what you want.