Listproc - Known Issues

Last Updated: 05/01/2014


Listed below are known issues related to Listproc functions as well as possible workarounds and/or progress toward resolution of the issues. If the suggested workarounds do not help you, or if you are having any issue at all, contact the IT Service Center (303-735-4357, 5-HELP from on-campus, or

Responding to Listproc Messages

  • Impact: If an Exchange user sends an email to a list and includes other addresses on the same To: or CC: lines, the emails will be delivered to the recipients fine. However, those recieving the email will notice in their email headers that extraneous text of "" gets appended to the last email address (be it another list, or an individual's email address). Thus, if the recipient replies to the email, the address with the appended text will bounce back as undeliverable.
  • Workaround: To avoid this, after selecting reply-to, manually remove the extraneous text before sending the email.
  • Last updated: May 1, 2012

Sending to a list from a Yahoo account

  • Impact: If an email is sent to a Listproc list from an account, the email sent from the list is from If there are any subscribers on the list with Yahoo addresses, emails will bounce with the following error:
    • (reason: 550 5.7.0 (BAY0-MC6-F3) Unfortunately, messages from ( on behalf of ( could not be delivered due to domain owner policy restrictions.)
      (reason: 554 5.7.9 Message not accepted for policy reasons. See
  • Workaround: Send the message to the list from the an email address.
  • Last updated: May 1, 2014

Extraneous Embedded HTML In Subscribers Addresses 

  • Impact: Subscriber address(es) have embedded HTML which throw undeliverable errors when an email is sent to the list. Sample broken data: <a href=\"\"></a> ACK 13261 34234 NO Anita Lunt
  • Workaround: To correct this, please email help@Colorado.EDU to request that the UCB listmaster manually edit and fix your subscriber file.
  • Last updated: May 11, 2012

Owner Is Unable to Administer a List

  • Impact: If you get the response from the list server of 'No command found' when you try to add or delete a subscriber and you know the command that you're using is correct, your email is likely embedding HTML in the command.  When this happens, the list server cannot understand what you're asking it to do.
  • Workaround: If the email account you're using to admin your list is on the new Exchange service, it could be that some list administrative commands are being sent as HTML instead of the required plain text format.  If you use Outlook when you create a new email message, click on the “Options” tab at the top of the untitled email message and then click “As Plain Text.” Then send your message to with your usual add or delete command (and a blank subject line). Also if you copy/paste email addresses into a plain text email, HTML code oftengets embedded in the subscriber address (even though the email is in plain text). Rather than copying/pasting, you may try to type in the subscriber's email address.
  • Last updated: May 11, 2012

Email addresses are dropped from headers when there are multiple list addresses

  • Impact: If multiple lists are included in an emailing, not all lists being sent to will show up in Exchange headers when the email to the lists is received by subscribers. The sender's email and the list server logs shows all of the list addresses being sent to. When the email is received (even by the person who sent it to the lists), one list is missing in the to: and cc: fields even though it was correctly delivered.
  • Workaround: There currently is no known workaround.
  • Last updated: May 11, 2012