New comment by leahneukirchen on mblaze repository

https://github.com/leahneukirchen/mblaze/issues/178#issuecomment-666322975

Comment:
This is MH terminology originally, it means the mails are moved from "new" to "cur" but not marked as read.

Maildir delivers mail to new/ but most of mblaze only looks at cur/, so you need to move the mail between that to work with it later.

```
  3. To unite with, or introduce into, a mass already formed;
as, to incorporate copper with silver; -- used with with and
into.
```