notification script running on git repos deployed and configured via a ansible playbook ...
In order to avoid git branches diverging to much from the main branch and/or to enforce timely intergation of changes made on the main branch on prominent files (test configurations, commit checks, submodules, ...) you can run a script on a checkout that will notify the author/commiter of the last commit on the branch in question by mail.
Many parameters can be configured, as the script is implemented as a jinja2 template.
Branches can be excludes via configuration or by setting a tag named $branch-archived on the HEAD commit of the branch. (if the tag is not pointing to the HEAD the script assumes the branch is still in use and will ignore the tag!)
see: defaults/main.yml