How do cold email tools handle tracking pixels?

Tracking pixels are the standard mechanism for measuring email opens. Understanding how they work helps interpret their limitations.

How tracking pixels work:

A unique 1x1 transparent image is embedded in each email

The image URL includes identifiers linking to the specific recipient

When the email is opened and images load, the pixel request is logged

The tool records an open event for that recipient

Implementation by cold email tools:

Pixels are automatically inserted into messages

Each send gets unique tracking identifier

Opens are logged in real-time to the campaign dashboard

Data feeds engagement reporting and sequence logic

Reliability problems:

Apple MPP pre-loads pixels, creating false opens

Image blocking prevents tracking entirely

Security tools may load pixels during scanning

Corporate gateways may strip tracking elements

Tool options:

Many tools allow disabling open tracking

Some offer privacy-respecting alternatives

Consider disabling for highest deliverability

Use reply detection as primary engagement signal

Opens are a signal, not a truth. The instrument shows a reading, but the reading may not reflect reality.