The first thing to do is to file a bug report. That makes other users aware of the issue you have discovered. Include a detailed description of the problem. Follow that up with uploading a suitable patch to your RT ticket so that others may choose to apply it. Uploading a test which proves that your patch fixes the bug is quite helpful, too.

Next, follow the procedures outlined on the CPAN FAQ:
How do I go about maintaining a module when the author is unresponsive?
How do I adopt or take over a module already on CPAN?

and here: PAUSE: taking over

In reply to Re: Mail::Bulkmail maintenance by toolic
in thread Mail::Bulkmail maintenance by soliplaya

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":