Does Drupal detect if the user register email could not be delivered and removes the account? I got this error message back from the MTA:


  This message was created automatically by mail delivery software (Exim).
  
  A message that you sent could not be delivered to one or more of its
  recipients. This is a permanent error. The following address(es) failed:
  
  #######@***.+++
     Connection timed out:
     retry timeout exceeded  


This is fine so far. What puzzles me is the fact that the created account disapeared. This is reproducible. The account was created again (same email address), the delivery error occoured again and the account disapeared.

Is this on purpose?
Drupal doesn't know about the status of the email. I'm not sure how Drupal 5 does it, but it would be possible to setup Drupal to delete accounts older than X that has never logged in.