How do I manage access to the email list?

Access to the email list is in almost all cases best limited to the moderator email address only. The email address selected during the creation of the email list can be used to further manage and use the email list by setting the moderator only option in the email list settings via the client panel.

So with the Posting permission set to only the moderator address, the email list can only be used with this email address. Or send to.

Other option you have to select is the option to also give the posting permission to the subscribers of the email list. Any subscriber of the list can then also use this. This is not desirable in most situations.

Further access to the settings of the email list is also possible via the webmail with the moderator email address, which can be viewed as domain administrator under domain settings -> Email list. This is only recommended for advanced users to further adjust settings here.