# use-email-id
Message identity and threading primitives for `RustUse`.
## Experimental
`use-email-id` is experimental while `use-email` remains below `0.3.0`.
## Example
```rust
use use_email_id::{InReplyTo, MessageId, References};
let root: MessageId = "<root@example.com>".parse()?;
let reply: MessageId = "reply@example.com".parse()?;
let references = References::new().with_message_id(root.clone()).with_message_id(reply.clone());
let in_reply_to = InReplyTo::new(root);
assert_eq!(reply.to_string(), "<reply@example.com>");
assert_eq!(references.len(), 2);
assert!(in_reply_to.to_string().contains("root@example.com"));
# Ok::<(), use_email_id::MessageIdError>(())
```
## Scope
- Message-ID local/domain wrappers and angle-bracket formatting.
- References, In-Reply-To, and thread reference containers.
- Conservative validation for typed identity strings.
## Non-goals
- Message store or mailbox threading algorithms.
- Global uniqueness guarantees.
- Complete RFC parser behavior.
## License
Licensed under either Apache-2.0 or MIT.