gajim-triggers software package provides configure Gajims behaviour for each contact, you can install in your Debian 9 (Stretch) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install gajim-triggers
gajim-triggers is installed in your system.
Make ensure the gajim-triggers package were installed using the commands given below,
$ sudo dpkg-query -l | grep gajim-triggers *
You will get with gajim-triggers package name, version, architecture and description in a table
| Distro | Debian 9 stretch |
| Section | Network |
| Package | gajim-triggers |
| Version | 0.1-1 |
| Description | configure Gajims behaviour for each contact |
| Sub Section | Net |