Available in a git repository.
Repository: mutt-ldap
Browsable repository: mutt-ldap
Author: W. Trevor King

I wrote this Python script to query an LDAP server for addresses from Mutt. In December 2012, I got some patches from Wade Berrier and Niels de Vos. Anything interesting enough for others to hack on deserves it's own repository, so I pulled it out of my blog repository (linked above, and mirrored on GitHub).

The README is posted on the PyPI page.