Impression and Click Tracking

MailAdx logs impressions at open time when the display URL is fetched, and clicks via redirect URLs — both designed to work correctly in email environments.

Impression tracking: open-time logging

When a subscriber opens your email, their client fetches the MailAdx display URL (/api/v1/serving/display). At that moment MailAdx runs the waterfall, selects the winning creative, and logs an impression. Impressions are only recorded for emails that were actually opened — not for every subscriber on your send list.

Each impression record contains: request ID, publisher ID, placement key, creative ID, line item ID, subscriber hash (SHA-256 of email), timestamp, and the decision outcome (which demand tier won, at what CPM). Records are available in the Reporting API within 2 minutes.

Click tracking: URL redirects

MailAdx wraps ad links through /api/v1/serving/click, which logs the click event before redirecting to the destination URL. This is a standard HTTP 302 redirect that works in all email clients. Click redirects add approximately 50–80ms of latency to the first navigation.

Gmail image proxy

Gmail caches remote images on its proxy servers. MailAdx uses a nonce-based bypass: the first fetch redirects to itself with a fresh randomised parameter, which Gmail caches per open while the original URL stays uncached — ensuring each genuine re-open triggers a fresh auction.

Apple Mail Privacy Protection

Apple MPP prefetches email images before delivery on Apple's relay servers. MailAdx detects the Apple Mail user agent and marks these impressions as "AppleMPP" in delivery reports, so you can distinguish them from genuine human opens in your analytics. See our Gmail and Apple MPP guide for details.

Disabling tracking for specific placements

For compliance reasons or specific advertiser requirements, click tracking can be disabled per placement. Note that click events will not be logged in MailAdx reporting for placements with tracking disabled. Configure per placement at Dashboard → Placements → [placement] → Advanced → Click Tracking.