couriergraph software package provides Mail statistics RRDtool frontend for Courier-{POP,IMAP}, you can install in your Ubuntu 16.10 (Yakkety Yak) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install couriergraph
couriergraph is installed in your system.
Make ensure the couriergraph package were installed using the commands given below,
$ sudo dpkg-query -l | grep couriergraph *
You will get with couriergraph package name, version, architecture and description in a table
| Distro | Ubuntu 16 10 yakkety yak |
| Section | Administration Utilities |
| Package | couriergraph |
| Version | 0.25-4.3 |
| Description | Mail statistics RRDtool frontend for Courier-{POP,IMAP} |
| Sub Section | admin |