enigmail software package provides GPG support for Thunderbird and Debian Icedove, 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 enigmail
enigmail is installed in your system.
Make ensure the enigmail package were installed using the commands given below,
$ sudo dpkg-query -l | grep enigmail *
You will get with enigmail package name, version, architecture and description in a table
| Distro | Ubuntu 16 10 yakkety yak |
| Section | |
| Package | enigmail |
| Version | 2:1.9.5-2 |
| Description | GPG support for Thunderbird and Debian Icedove |
| Sub Section |