Integration with Mailalias?

Hi! I think this is a feature request, but I'm new to Drupal, so forgive me if I've missed something and it's actually a support request!

I'm using Listhandler to archive a mailing list on a Drupal forum. Most mailing list members are already users in Drupal, and if they have a second email address that I know about, it's often (but not always!) already defined in Mailalias. Brand new list members posting for the first time have a Drupal account automatically created. So far, so good...

The problem occurs when an existing user posts from a second email address which isn't known to Mailalias. Listhandler then cannot create a new user (Cannot create account: The name 'Ian Harris' is already taken.) and the incoming email gets posted as "Anonymous". On my site this fails because I do not allow anonymous postings (eg "Comment: unauthorized comment submitted or comment submitted to a closed post..."). But even if I were to allow anonymous content, it'd still end up being filed under Anonymous, rather than the correct user.

Would it be possible for Listhandler to automatically add email addresses to Mailalias, should its attempt to create a new user fail due to the username being already taken?