Open Events
When using Aftersend (or any insight add-in), it is not always possible to track when an email is opened. This is because each mail client (and organisation) has different security options to allow or disallow external content.
IP Information
Occasionally, you may see that the location and IP address information for events are inaccurate, and may show the names of certain email providers instead of commercial ISPs. This is typically because the recipient's mail client/provider is using a proxy service to obscure identifying data of the recipient.