After many years of good work with Trac, I've finally decided to replace it by Redmine.
Trac is a really good product but lacks of many interesting features (like the multi-projects one). Redmine seems to be a good candidate and is more simple to deploy.
The new project page is available here : Modoboa redmine instance.
Many thanks to the state-of-mind team who provide a lot of help to achieve the migration :-)