NorthernTrail Outfitters (NTO) is launching a custom, corporate-branded apparel website. They are concerned about the new initiative's campaign impacting deliverability on its consumer retail sends. NTO has purchased a second IP address to be used for the corporate site's email sending.
What feature would the NTO administrator use to specify which IP address is used for retail vs. corporate?

Northern Train Outfitters wants to identify subscribers with something other than an email address. What value can be used to accommodate this?

Which metric is the measure of emails rejected by a server due to permanent conditions such as"user unknown" or "domain not found"?

A marketer at Northern Train Outfitters has been tasked with growing its email subscriber audience.
Which three best practices should the marketer keep in mind while trying to acquire new email subscribers?

Northern Trail Outfitters (NTO) is currently sending out a single welcomeemail when a subscriber joins its myNTO Rewards program. NTO wants to test whether one, two, or three welcome emails would result in a higher rate of conversion.
How can this be accomplished most efficiently?