[Mailman-Users] Bounce emails

[Sullivan, John]

Hi - I send out a newsletter to about 50k subscribers - I've been sending
them out for about 2 weeks now. Today I received in my admin mailbox a few
thousand messages like this one below. Can anyone explain to me what this is
and what's going on - thanks. I didn't configure anything for bounce mails
everything to the best of my knowledge is set to the defaults. 



Subject: 90minutes member sokk345ay at aol.com bouncing - disabled

Content-type: text/plain; charset=us-ascii

This is a Mailman mailing list bounce action notice:

    List:       90minutes
    Member:     sokk345ayr at aol.com
    Action:     Subscription disabled.
    Reason:     Excessive or fatal bounces.
    

You can reenable their subscription by visiting the membership management
page at http://lists.domain.com/mailman/admin/90minutes/members and setting
their options accordingly

The triggering bounce notice is attached below.

Questions?  Contact the Mailman site administrator at