Email from: address: how to set for each subsite?

The usage (https://premium.wpmudev.org/project/subscribe-by-email/#usage) for Subscribe by Email shows a place on general settings to set the sending email address. I do not see this field on the general settings on our subsites. We do not network activate the plugin, as it is not needed on all sites. how do we ensure the no-reply@somesubsite.domain.edu gets set correctly for each subsite?
(I have reviewed this thread in the forums: https://premium.wpmudev.org/forums/topic/subscribe-by-email-noreplay-address-settings but we do not use caching or smtp.) The plugin is working well on subsites, it just doesn't show individual subsite no-reply@subsite-or-mapped-domain.edu. Please tell me what I am missing or have overlooked. I am really stumped about not having the field in general settings that is shown on the usage page...