>      Listmembers,
>
>                                      List related ID, and E-mail
> addresses have been altered below.
> Looking for reasonable explaination regarding  "Daily Monitoring Error
> Report" issued at 00:00:03, Dec. 15/03.
>
> Err First Last  Address
> --- ----- ----- -------
>   1 12/14 12/14 [log in to unmask]
>                 Last error: 550 Host 'EMAIL2ME.COMMAIL.COM' Unknown
>
> My List is running on Listserv TCP/IP VM ver. 1.8D under CMC
> (CMSprog=X'16').
>
> There were absolutely "NO" List postings between 12/12/03 at 16:34, and
>
> 12/15/03 at 05:20.
>
> "NO" subscriber from "COMMAIL.COM" domain has ever been a List member. "NO"
> 5LUVVFUJ@*.* has ever been a List member. The "COMMAIL.COM" domain has been
> blacklisted in several databases.
>
> List Header:
>
> PUT XXXXXX LIST PW=XXXXXXXXXX
> * NNNNN  MMMMMMM OOOOO
> * .HH ON
> * Owner= [log in to unmask]
> * Owner= quiet: [log in to unmask] (BBBBB CCCCCC)
> * Owner= [log in to unmask] (XVVVV XDDDD)
> * Attachments= No,Filter
> * Auto-Delete= Yes,Full-Auto
> * Daily-Threshold= 100,8
> * Default-Options= Repro,Subjecthdr
> * Default-Topics= OTHER
> * Digest= Yes,Same,Daily,22
> * Editor= [log in to unmask]
> * Editor-Header= No
> * Errors-To= Owner
> * Files= No
> * Language= NoHTML
> * Mail-Via= Distribute
> * Notebook= Yes,n,Weekly,Owner
> * Notify= Yes
> * Reply-To= List,Respect
> * Review= Owner
> * Send= (LIST NAME)
> * SizeLim= 150
> * Stats= Normal,Owner
> * Subject-Tag= XXXXX
> * Subscription= By Owner
> * Topics= ZZZZX,TEST
> * Validate= No
> * .HH OFF
>
> My concern here is how and why is this error being generated through my
> host mail server and Listserv??

1. Spammer sends message to the xxx list with a non-existent From:
2. LISTSERV responds with "you are not allowed to post to this list"
3. Non-existent address bounces.
4. Since the message and response was for the xxx list, LISTSERV records
   the fatal bounce for xxx list.