The industry standard of email open tracking is based on the web beacon (or the tiny piece of code which requests a tiny invisible image from our servers) when it is received.
There are some limitations of the web beacon which you should be aware of.
- 1. Automated replies (out-of-office responses) generally are not recorded as an open as they don't download the web beacon
- 2. The web beacon does not work in plain text campaigns
- - However if a link is clicked in a plain-text campaign the open will still be recorded
- - Generally a very small minority of subscribers will have email addresses set up to receive plain-text campaigns
- 3. If a subscriber or their email client have set or selected not to display images automatically, if they don't click on any links then it won't display as an open, even if they may have reviewed some of the content.