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.

Type
Text
Category
Contact Lists
Tags
contact list