lots of unecessary HM messages

I've noticed this weird behaviour when I use the latest HM. When a message sent to a mailing list returns to sender (majordomo-owner eventually) the message also contains all the HM messages (example below). This never used to happen before (HM 2.0b3) until I switched to the latest HM.

Is this a bug?
It's not preventing things from functioning properly, it's just that majordomo-owner's mailbox gets filled with multiple 200K messages in my case...

Is there anything I can do to prevent this from happening?

Thanks,

Otis

• The following addresses had permanent fatal errors ----- foo_at_bar.com (expanded from: :include:/home/majordomo/lists/zine-talk)
• Transcript of session follows ----- 451 /home/majordomo/lists/zine-talk: line 288: user_at_host1.com... host1.com: Name server timeout message 0: Message-ID missing, using 929376531.0000_at_hypermail.dummy instead. message 2: Message-ID missing, using 929376531.0001_at_hypermail.dummy instead. message 3: Message-ID missing, using 929376531.0002_at_hypermail.dummy instead. message 4: Message-ID missing, using 929376531.0003_at_hypermail.dummy instead.
  ...
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