Every list must have at least one list owner. The header entry for the primary list owner must be associated with your primary Rider email account. This is defined by one of more * Owner= lines in the list header configuration.
An owner is defined as a person with the ability to edit the list header configuration, and add or remove subscribers to a list. An owner does not have the ability to post email to or receive email from the list, unless they are also listed as a subscriber. Do not assume that since they are an owner then they can "do anything."
If * Errors-to= Owner (singular) is displayed in the list header configuration, then the first owner listed (nearest the top of the header) receives all the error messages. If * Errors-to= Owners (plural) is displayed, all the owners receive any error messages.
An editor is only needed for a moderated list (only when * Send= Editor is used in the list header configuration.) If * Send= Public or Send= Private is used, an editor is meaningless.
An editor is defined as a person with the ability to post to a moderated list. The first editor listed (nearest the top of the header) acts as the moderator. They receive all the postings from subscribers to approve. If you want all the editors to be able to approve posting, you must use the keyword * Moderator= All, emailaddress1, emailaddress2, ...
An editor will not receive list email unless they are also subscribed to the list.