Open rate tracking

You can enable open-rate tracking to see how often messages sent to a group appear to be opened by recipients.  Open rate tracking can be enabled in your group settings.

Methodology

Open-rate tracking is implemented using a tracking pixel that is loaded when an email is opened. However, tracking email opens is inherently imprecise and can only ever provide an indication of engagement, not a definitive count of how many people have read a message. Some email clients block images entirely, others load them automatically for security or privacy reasons, and modern privacy features can obscure when or whether a real person opened an email. As a result, open rates may be under- or over-reported.

Open Rate Index (ORI)

For this reason, we don't present open rates as a simple percentage. Instead, we show an Open Rate Index that indicates how a message performed relative to other messages within the same group.  The index ranges from 0 (indicating a message hasn't been opened by anyone) to 10 (indicating, as far as we can tell, that everyone has opened it).

Because all messages in a group are affected by the same email clients and privacy behaviours, this relative view provides a more reliable way to understand engagement over time without implying a level of accuracy that open-rate tracking cannot guarantee.

When an open is recorded, Gaggle Mail categorises it based on the information available at the time the tracking pixel is loaded:

• Human open – the user agent clearly identifies a mail application or browser used by a person.
• Proxy open – the request comes from a known email or security proxy that loads images on behalf of the recipient.
• Privacy open – the request is made by a service designed to deliberately obscure user behaviour, such as privacy-enforcing mail features.
• Unknown open – there is insufficient information to reliably identify the source of the request.

These categories are used to inform the Open Rate Index and provide additional context, rather than to imply certainty about individual recipient behaviour.