How to eliminate duplicate emails from Reply All

If your mailing list is configured for replies to go to the Author of the message, then a Reply All from a subscriber will send a copy of their reply directly to the Author, plus a copy to the mailing list.

The mailing list will then send a second copy of that email to the Author, since the Author is also a member of the list.

Use the web interface to change settings:

Log into your mail-list account at

  • Click Customize Your List.
  • Click Miscellaneous Settings.
  • Click Eliminate Duplicate Emails from Reply All.
  • Select Suppress Duplicate.
  • Click Save.

If the setting Have Replies Go Back to List by Default is set to Reply to List, then Eliminate Duplicate Emails From Reply All is grayed out.

In this case, all replies automatically go to the list, so duplicate emails is not an issue.