WebCom's Email Distribution List service does not allow for customizing the Reply-To field of messages sent through the list, the Reply-To address will always be that of the sender. The reason this is disallowed is because many mail servers on the Internet improperly send error messages (like bounced messages from nonexistent email addresses) to the Reply-To address, instead of to the Return-Path address as is specified by Internet standards.

If the Reply-To address contains the address of the list, then a bounced message from a non-existant email address could be improperly sent back to the list, which in turn is distributed to the entire list, and a mail loop results.