What do these columns mean clickts, viewts, clickip, viewip inside a list?

These columns are tracking columns that are used for email marketing campaigns.

clickts – is the date/time that someone clicked a link

clickip – is the IP address of the person that clicked the link

viewts – is the date/time that someone viewed the message

viewip – is the IP address of the person that viewed the message.

 

These columns are overwritten anytime a list is used in a campaign and stores the last time a user viewed a message or clicked a link.

What does active mean on the view lists page and why is it different than the total emails?

The active number on the "view lists" page refers to the number of email addresses that are still valid to send to on your next campaign.

The active number is any email that is not part of the inactive or suppressed email groups.

This number changes when you send out emails or if an address no longer exists the active count will go down.