Proposed commit log message:
```
[NEW PORT]: mail/mblaze: Unix utilities to deal with Maildir
The mblaze message system is a set of Unix utilities for processing and
interacting with mail messages which are stored in maildir folders.
WWW: https://github.com/chneukirchen/mblaze
Reviewed_by: koobs, mat
Approved by: koobs (mentor)
Differential_Revision: D16759
```