Following is a partial list of LISTSERV error messages as well as a description of some problems and possible solutions.

    Subscribers who have subscribed using, or other services may not receive some or all listserv messages.  They also will not be able to confirm their post to listserv.

    The fix to allow receipt of most messages is to change your listserv unsubscribe link.  Directions for this can be found under the "How Can I Add a Link For Users to Unsubscribe From My List?" section of this page:

    Subscribers who wish to post will need to send their email to the List Owner and ask them to post for them or they will need to subscribe with another email account that is NOT hosted by

    More details:

    Reported error: 550 5.0.350 Remote server returned an error -> 554 Message not allowed - [PH01] Email not accepted for policy reasons.  Please visit

    We have narrowed the issue down to the listserv command line which contains wa.exe? as part of the command.  This is part of all ListServ emailed commands including message confirmation and some unsubscribe links.


    These tend to be a bad address in the subscriber list and the address will need to be removed from the list.

    • Possible delivery error .... Domain "xxxxxxxx" doesn't exist
    • Possible delivery error .... User unknown
    • Possible delivery error .... email address lookup in domain map failed


    1. Log In to LISTSERV
    2. In the "Select List:" pulldown menu, choose the listname you need to edit
    3. Click Subscriber Management (in List Management section on left side of screen)
    4. In the "Search for Subscribers (listname)" field, type or copy in the bad address
    5. Click Search
    6. Select Do not notify the user in any way and click Delete to delete this address

    The message "The enclosed message has been identified as a delivery error for the listname list because it was sent to 'owner-listname@LIST.UIOWA.EDU' is a warning to you, the list owner, of a possible error condition.

    List errors are normally sent to owner-listname@LIST.UIOWA.EDU. These messages are forwarded to the list owner with the above warning. It is up to you to determine the error. These messages will be sent to the alias in the "errors-to:" in the list headers if that keyword is set. Sometimes you may receive a message that looks like an error when actually someone meant to sent a message to the list owner, but incorrectly addressed the e-mail to owner-listname@LIST.UIOWA.EDU. The preferred address for sending a message to the list owner is listname-request@LIST.UIOWA.EDU.   For more information see the List Owner's Manual Section 4.7.2 The owner-listname address.

    This happens when you receive your messages as "Digest (traditional) NOMIME DIGEST". Change your Subscription type to either "Digest (MIME format) NOHTML MIME DIGEST" or "Digest (HTML format) HTML Digest".

    • Digest (MIME format) NOHTML MIME DIGEST - will send the attachment.
    • Digest (HTML format) HTML Digest - will send the digest as html and provide a link to the archives for viewing the attachments.
    Article number: 
    Last updated: 
    February 12, 2024