The Guest List displays two ways to track emails: Last Contacted, and Last Email Interaction.
Last Contacted displays the time Event Farm received a request to send or re-send an invitation, confirmation, or declination email.
Last Email Interaction displays statuses for the most-recently sent email to a guest. This includes Invitations, Confirmations, Declinations, and Send a Message Message Types.
Several statuses rely on information being sent from the guest's email server - or from the guest's email client (Outlook, Mail for Mac and iOS, Gmail or Yahoo Mail apps) - back to Event Farm. Below are the Last Email Interaction statuses found in the Guest List and some reports, as well as how Event Farm determines the status.
Received: Request received by us to send email
Processed ("Injection" in some reports): Email has been sent
Delivered: Email delivered. We request this information from the recipient's email server, and the server decides whether or not to send that information back to Event Farm.
Opened: Email has been opened. This is determined by a tracking pixel, a tiny image. Email clients, email services (especially Gmail), and networks can block tracking pixels.
Clicked: Link inside email has been clicked and guest has visited our website
Bounced: Email not delivered. The recipient's server tells us it is not a valid email address.
Additional statuses and definitions can be found in Email Statistics Definitions.