If you have found a bug in the ezmlm-idx additions, please send a bug report by email to firstname.lastname@example.org. Describe the error, your setup, and your system in sufficient detail so that it can be reproduced by third parties. Include relevant sections of mail log, and information about any error messages returned. If you ran into a problem and resolved it on your own, include a fix as a context diff against the distribution.
If you have found a bug in ezmlm proper (unlikely), please send a similar bug report to email@example.com or firstname.lastname@example.org. If you're unsure where the bug is, you can start with email@example.com. If you have problems and questions, please refer to the documentation, then to mailing list archives, then email the ezmlm mailing list or the authors.