[Mailman-Users] How could this happen? - Post to moderated list

[Edward Ned Harvey]

I have a list, with the following values:
    accept_these_nonmembers
        ^((^.*@lyricsemi.com)|(^.*@lyricsemiconductor.com)|(^.*@lyricsemiconductors.com))
        Should accept all messages from anyone in my domain, regardless of whether or not the poster is subscribed.

Members:
       Includes joe.user at lyricsemiconductor.com

However, Joe User posted a message to the list, and he got the auto response "Awaiting moderator approval" and "Reason: Post to moderated list."

I noticed just now - When I look at the membership status, Joe User has the checkbox next to his name, under the "mod" column.  Does this imply that he is being forcefully moderated?  How could that checkbox have gotten set?  I am the moderator, and I don't want him moderated, and I never set that box explicitly for him.

Obviously I got past the problem this time by simply accepting his message.  But I'd like to know what caused it so I can avoid future issues.

Thanks...