Add a retirement note in the README

## Retired project

This Apache James sub-project had been retired on the 30/07/2021.

[Read more](https://www.mail-archive.com/server-dev@james.apache.org/msg70608.html)
1 file changed
tree: 5aecb0c50fafc05760792dd949362f67f0302cb6
  1. docs/
  2. src/
  3. build.xml
  4. HOWTO
  5. LICENSE
  6. NOTICE
  7. pom.xml
  8. README.md
  9. RETIRED_PROJECT
  10. TODO
README.md